%&latex \NeedsTeXFormat{LaTeX2e} % sorry, compatibility with 2.09 is too painful \documentclass[]{tdsguide} \usepackage{times} \tdsVersion{0.9991} \title{A Directory Structure for \TeX{} Files} \author{TUG Working Group on a \TeX{} Directory Structure (TWG-TDS)} \begin{document} \maketitle \begin{legalnotice} Copyright {\copyright} 1994, 95, 96 by the \TeX{} Users Group. Permission to use, copy, and distribute this document for any purpose \emphasis{without modification} and without fee is hereby granted, provided that this notice appears in all copies. It is provided ``as is'' without expressed or implied warranty. Permission is granted to copy and distribute modified versions of this document under the conditions for verbatim copying, provided that the modifications are clearly marked and the document is not represented as the official one. This document is available on any \abbr{ctan} host (Appendix~\ref{sec:Related references} has a complete reference). Please send questions or suggestions by email to \email|twg-tds@mail.tug.org| or by postal mail to Karl Berry / 135 Center Hill Road / Plymouth, MA\ \ 02360 / USA\@. We welcome all comments. \end{legalnotice} %\newpage \tableofcontents \newpage \section{Introduction} \TeX{} is a powerful, flexible typesetting system used by thousands of people around the world. It is extremely portable and runs on virtually all operating systems. One unfortunate side effect of \TeX{}'s flexibility, however, is that there has been no single ``right'' way to install it. This has resulted in many sites having different installed arrangements. The primary purpose of this document is to describe a standard \TeX{} Directory Structure (\abbr{TDS}): a directory hierarchy for macros, fonts, and the other implementation-independent \TeX{} system files. As a matter of practicality, this document also suggests ways to incorporate the rest of the \TeX{} files into a single structure. The \abbr{TDS} has been designed to work on all modern systems. In particular, the Technical Working Group (TWG) believes it is usable under Mac\abbr{OS}, \abbr{ms-dos}, \abbr{os/2}, Unix, \abbr{vms}, and Windows \abbr{nt}\@. We hope that administrators and developers of both free and commercial \TeX{} implementations will adopt this standard. This document is intended both for the \TeX{} system administrator at a site and for people preparing \TeX{} distributions---everything from a complete runnable system to a single macro or style file. It may also help \TeX{} users find their way around systems organized this way. It is not a tutorial: we necessarily assume knowledge of the many parts of a working \TeX{} system. If you are unfamiliar with any of the programs or file formats we refer to, consult the references in Appendix~\ref{sec:Related references}. \subsection{The role of the \abbr{TDS}} The role of the \abbr{TDS} is to stabilize the organization of \TeX{}-related software packages that are installed and in use, possibly on multiple platforms simultaneously. At first glance, it may seem that the Comprehensive \TeX{} Archive Network (\abbr{ctan}) archives fulfill at least part of this role, but this is not the case. The role of \abbr{ctan} is to simplify archiving and distribution, not installation and use. In fact, the roles of the \abbr{TDS} and \abbr{ctan} are frequently in conflict, as you will see elsewhere in this document. For distribution, many different types of files must be combined into a single unit; for use, it is traditional to segregate files (even similar files) from a single package into separate, occasionally distant, directories. \subsection{Conventions} In this document, ``\path|/|'' is used to separate filename components; for example, \path|texmf/fonts|. This is the Unix convention but the ideas are in no way Unix-specific. In this document, ``\TeX{}'' generally means the \TeX{} system, including \MF{}, \abbr{DVI} drivers, utilities, etc., not just the \TeX{} program itself. The word ``package'' in this document has its usual meaning: a set of related files distributed, installed, and maintained as a unit. This is \emphasis{not} a \LaTeXe{} package, which is a style file supplementing a document class. We use the following typographic conventions: \begin{description} \item[\literal{literal}] Literal text such as \literal{filename} is typeset in typewriter type. \item[\replaceable{replaceable}] Replaceable text such as \replaceable{package}, identifying a class of things, is typeset in italics inside angle brackets. \end{description} \section{General} This section describes common properties throughout the \abbr{TDS} tree. \subsection{Subdirectory searching} \label{sec:Subdirectory searching} Many \TeX{} installations store large numbers of related files in single directories, for example, all \path|TFM| files and\slash or all \TeX{} input files. This monolithic arrangement hinders maintenance of a \TeX{} system: it is difficult to determine what files are used by what packages, what files need to be updated when a new version is installed, or what files should be deleted if a package is removed. It is also a source of error if two or more packages happen to have input files with the same name. Therefore, the \abbr{TWG} felt each package should be in a separate directory. But we recognized that explicitly listing all directories to be searched would be unbearable. A site may wish to install dozens of packages. Aside from anything else, listing that many directories would produce search paths many thousands of characters long, overflowing the available space on some systems. Also, if all directories are explicitly listed, installing or removing a new package would mean changing a path as well as installing or removing the actual files. This would be a time-consuming and error-prone operation, even with implementations that provide some way to specify the directories to search at runtime. On systems without runtime configuration, it would require recompiling software, an intolerable burden. As a result, the \abbr{TWG} concluded that a comprehensive \abbr{TDS} requires implementations to support some form of implicit subdirectory searching. More precisely, implementations must make it possible to specify that \TeX{}, \MF{}, and their companion utilities search in both a specified directory and recursively through all subdirectories of that directory when looking for an input file. Other forms of subdirectory searching, for example recursive-to-one-level searches, may also be provided. We encourage implementors to provide subdirectory searching at the option of the installer and user for all paths. The \abbr{TDS} does not specify a syntax for specifying recursive searching, but we encourage implementors to provide interoperability (see Section~\ref{sec:More on subdirectory searching}). \subsection{Rooting the tree} \label{sec:Rooting the tree} In this document, we shall designate the root \abbr{TDS} directory by `\texmf{}' (for ``\TeX{} and \MF{}''). We recommend using that name where possible, but the actual name of the directory is up to the installer. On \abbr{pc} networks, for example, this could map to a logical drive specification such as \path|T:|. Similarly, the location of this directory on the system is site-dependent. It may be at the root of the file system; on Unix systems, \path|/usr/local/share|, \path|/usr/local|, \path|/usr/local/lib|, and \path|/opt| are common choices. The name \texmf{} was chosen for several reasons: it reflects the fact that the directory contains files pertaining to an entire \TeX{} system (including \MF{}, \MP{}, \BibTeX{}, etc.), not just \TeX{} itself; and it is descriptive of a generic installation rather than a particular implementation. A site may choose to have more than one \abbr{TDS} hierarchy installed (for example, when installing an upgrade). This is perfectly legitimate. \subsection{Local additions} \label{sec:Local additions} The \abbr{TDS} cannot specify precisely when a package is or is not a ``local addition''. Each site must determine this according to their own conventions. At the two extremes, one site might wish to consider ``nonlocal'' only those files that came with the particular \TeX{} distribution they installed; another site might consider ``local'' only those files that were actually developed at the local site and not distributed elsewhere. We recognize two common methods for local additions to a distributed \texmf{} tree. Both have their place; in fact, some sites may employ both simultaneously: \begin{enumerate} \item A completely separate tree which is a \abbr{TDS} structure itself; for example, \path|/usr/local/umbtex| at the University of Massachusetts at Boston. This is another example of the multiple \texmf{} hierarchies mentioned in the previous section. \item A directory named `\path|local|' at any appropriate level, for example, in the \replaceable{format}, \replaceable{package}, and \replaceable{supplier} directories discussed in the following sections. The \abbr{TDS} reserves the directory name \path|local| for this purpose. We recommend using \path|local| for site-adapted configuration files, such as \path|language.dat| for the Babel package or \path|graphics.cfg| for the graphics package. Unmodified configuration files from a package should remain in the package directory. The intent is to separate locally modified or created files from distribution files, to ease installing new releases. \end{enumerate} One common case of local additions is dynamically generated files, e.g., \path|PK| fonts by the \path|MakeTeXPK| script originated by \application{Dvips}. A site may store the generated files directly in any of: \begin{itemize-squeeze} \item their standard location in the main \abbr{TDS} tree (if it can be made globally writable); \item an alternative location in the main \abbr{TDS} tree (for example, under \path|texmf/fonts/tmp|); \item a second complete \abbr{TDS} tree (as outlined above); \item any other convenient directory (perhaps under \path|/var|, for example \path|/var/spool/fonts|). \end{itemize-squeeze} No one solution will be appropriate for all sites. \subsection{Duplicate filenames} \label{sec:Duplicate filenames} Different files by the same name may exist in a \abbr{TDS} tree. The \abbr{TDS} generally leaves unspecified which of two files by the same name in a search path will be found, so generally the only way to reliably find a given file is for it to have a unique name. However, the \abbr{TDS} requires implementations to support the following exceptions: \begin{itemize} \item Names of \TeX{} input files must be unique within each first-level subdirectory of \path|texmf/tex| and \path|texmf/tex/generic|, but not within all of \path|texmf/tex|; i.e., different \TeX{} formats may have files by the same name. (Section~\ref{sec:Macros} discusses this further.) Thus, no single format-independent path specification, such as a recursive search beginning at \path|texmf/tex| specifying no other directories, suffices. So implementations must provide format-dependent path specifications, for example via wrapper scripts or configuration files. \item Many font files will have the same name (e.g., \path|cmr10.pk|), as discussed in Section~\ref{sec:Valid font bitmaps}. Implementations must distinguish these files by mode and resolution. \end{itemize} All implementations we know of already have these capabilities. One place where duplicate names are likely to occur is not an exception: \begin{itemize} \item Names of \MF{} input files (as opposed to bitmaps) must be unique within all of \path|texmf/fonts|. In practice, this is a problem with some variants of Computer Modern which contain slightly modified files named \path|punct.mf|, \path|romanl.mf|, and so on. We believe the only feasible solution is to rename the derivative files to be unique. \end{itemize} \section{Top-level directories} The directories under the \texmf{} root identify the major components of a \TeX{} system (see Section~\ref{sec:Summary} for a summary). A site may omit any unneeded directories. Although the \abbr{TDS} by its nature can specify precise locations only for implementation-independent files, we recognize that installers may well wish to place other files under \texmf{} to simplify administration of the \TeX{} tree, especially if it is maintained by someone other than the system administrator. Therefore, additional top-level directories may be present. The top-level directories specified by the \abbr{TDS} are: \begin{description} \item[\path|tex|] for \TeX{} files (Section~\ref{sec:Macros}). \item[\path|fonts|] for font-related files (Section~\ref{sec:Fonts}). \item[\path|metafont|] for \MF{} files which are not fonts (Section~\ref{sec:Non-font MF files}). \item[\path|metapost|] for \MP{} files (Section~\ref{sec:MetaPost}). \item[\path|bibtex|] for \BibTeX{} files (Section~\ref{sec:BibTeX}). \item[\path|doc|] for user documentation (Section~\ref{sec:Documentation}). \item[\path|source|] for sources. This includes both traditional program sources (for example, \application{Web2c} sources go in \path|texmf/source/web2c|) and \LaTeX{} \path|dtx| sources (which go in \path|texmf/source/latex|). The \abbr{TDS} leaves unspecified any structure under \path|source|. \path|source| is intended for files which are not needed at runtime by any \TeX{} program; it should not be included in any search path. For example, \path|plain.tex| does not belong under \path|texmf/source|, even though it is a ``source file'' in the sense of not being derived from another file. (It goes in \path|texmf/tex/plain/base|, as explained in Section~\ref{sec:Macros}). \item[\replaceable{implementation}] for implementations (examples: \path|emtex|, \path|web2c|), to be used for whatever purpose deemed suitable by the implementor or \TeX{} administrator. Files that cannot be shared between implementations, such as pool files (\path|tex.pool|) and memory dump files (\path|plain.fmt|) go here, in addition to implementation-wide configuration files. See Section~\ref{sec:Example implementation-specific trees} for examples of real \replaceable{implementation} trees. \item[\replaceable{program}] for individual configuration files and program-specific input files for \TeX{}-related programs (examples: \path|mft|, \path|dvips|). In fact, the \path|tex|, \path|metafont|, \path|metapost|, and \path|bibtex| directories above may be seen as instances of this case. \end{description} \subsection{Macros} \label{sec:Macros} \TeX{} macro files shall be stored in separate directories, segregated by \TeX{} format and package name (we use `format' in its traditional \TeX{} sense to mean a usefully \path|\dump|-able package): \begin{ttdisplay} texmf/tex/\replaceable{format}/\replaceable{package}/ \end{ttdisplay} \begin{description} \item[\replaceable{format}] is a format name (examples: \path|amstex|, \path|latex|, \path|plain|, \path|texinfo|). The \abbr{TDS} allows distributions that can be used as either formats or packages (e.g., Texinfo, Eplain) to be stored at either level, at the option of the format author or \TeX{} administrator. We recommend that packages used as formats at a particular site be stored at the \replaceable{format} level: by adjusting the \TeX{} inputs search path, it will be straightforward to use them as macro packages under another format, whereas placing them in another tree completely obscures their use as a format. The \abbr{TDS} reserves the following \replaceable{format} names: \begin{itemize} \item \path|generic|, for input files that are useful across a wide range of formats (examples: \path|null.tex|, \path|path.sty|). Generally, this means any format that uses the category codes of Plain \TeX{} and does not rely on any particular format. This is in contrast to those files which are useful only with Plain \TeX{} (which go under \path|texmf/tex/plain|), e.g., \path|testfont.tex| and \path|plain.tex| itself. \item \path|local|, for local additions. See Section~\ref{sec:Local additions}. \end{itemize} Thus, for almost every format, it is necessary to search at least the \replaceable{format} directory and then the \path|generic| directory (in that order). Other directories may need to be searched as well, depending on the format. When using \AMSTeX{}, for example, the \path|amstex|, \path|plain|, and \path|generic| directories should be searched, because \AMSTeX{} is compatible with Plain. \item[\replaceable{package}] is a \TeX{} package name (examples: \path|babel|, \path|texdraw|). In the case where a format consists of only a single file and has no auxiliary packages, that file can simply be placed in the \replaceable{format} directory, instead of \replaceable{format}\path|/base|. For example, Texinfo goes in \path|texmf/tex/texinfo/texinfo.tex|, not \path|texmf/tex/texinfo/base/texinfo.tex|. The \abbr{TDS} reserves the following \replaceable{package} names: \begin{itemize} \item \path|base|, for the base distribution of each format, including files used by \iniTeX{} when dumping format files. For example, in the standard \LaTeX{} distribution, the \path|ltx| files created during the build process shall be stored in the \path|base| directory. \item \path|hyphen|, for hyphenation patterns, including the original American English \path|hyphen.tex|. These are typically used only by \iniTeX{}. In most situations, this directory need exist only under the \literal{generic} format. \item \path|images|, for image input files, such as Encapsulated PostScript figures. Although it is somewhat non-intuitive for these to be under a directory named ``\path|tex|'', \TeX{} needs to read these files to glean bounding box or other information. A mechanism for sharing image inputs between \TeX{} and other typesetting programs (e.g., Interleaf, FrameMaker) is beyond the scope of the \abbr{TDS}\@. In most situations, this directory need exist only under the \literal{generic} format. \item \path|local|, for local additions and configuration files. See Section~\ref{sec:Local additions}. \item \path|misc|, for packages that consist of a single file. An administrator or package maintainer may create directories for single-file packages at their discretion, instead of using \path|misc|. \end{itemize} \end{description} \subsection{Fonts} \label{sec:Fonts} Font files shall be stored in separate directories, segregated by file type, font supplier, and typeface (\path|PK| and \path|GF| files need additional structure, as detailed in the next section): \begin{ttdisplay} texmf/fonts/\replaceable{type}/\replaceable{supplier}/\replaceable{typeface}/ \end{ttdisplay} \begin{description} \item[\replaceable{type}] is the type of font file. The \abbr{TDS} reserves the following \replaceable{type} names: \begin{itemize-squeeze} \item \path|afm|, for Adobe font metrics. \item \path|gf|, for generic font bitmap files. \item \path|pk|, for packed bitmap files. \item \path|source|, for font sources (\MF{} files, property lists, etc.). \item \path|tfm|, for \TeX{} font metric files. \item \path|type1|, for Type 1 fonts (in any format). \item \path|vf|, for virtual fonts. \end{itemize-squeeze} As usual, a site may omit any of these directories that are unnecessary (\path|gf| is a particularly likely candidate for omission). \item[\replaceable{supplier}] is a name identifying font source (examples: \path|adobe|, \path|ams|, \path|public|). The \abbr{TDS} reserves the following \replaceable{supplier} names: \begin{itemize} \item \path|ams|, for the American Mathematical Society's \AmS{}-fonts collection. \item \path|local|, for local additions. See Section~\ref{sec:Local additions}. \item \path|public|, for freely redistributable fonts where the supplier neither (1)~requested their own directory (e.g., \path|ams|), nor (2)~also made proprietary fonts (e.g., \path|adobe|). It does not contain all extant freely distributable fonts, nor are all files therein necessarily strictly public domain. \item \path|tmp|, for dynamically-generated fonts, as is traditional on some systems. It may be omitted if unnecessary, as usual. \end{itemize} \item[\replaceable{typeface}] is the name of a typeface family (examples: \path|cm|, \path|euler|, \path|times|). The \abbr{TDS} reserves the following \replaceable{typeface} names: \begin{itemize} \item \path|cm| (within \path|public|), for the 75 fonts defined in \citetitle{Computers and Typesetting, Volume~E}. \item \path|latex| (within \path|public|), for those fonts distributed with \LaTeX{} in the base distribution. \item \path|local|, for local additions. See Section~\ref{sec:Local additions}. \end{itemize} \end{description} Some concrete examples: \begin{ttdisplay} texmf/fonts/source/public/pandora/pnr10.mf texmf/fonts/tfm/public/cm/cmr10.tfm texmf/fonts/type1/adobe/utopia/putr.pfa \end{ttdisplay} For complete supplier and typeface name lists, consult \citetitle{Filenames for \TeX{} fonts} (see Appendix~\ref{sec:Related references}). \subsubsection{Font bitmaps} Font bitmap files require two characteristics in addition to the above to be uniquely identifiable: (1)~the type of device (i.e., mode) for which the font was created; (2)~the resolution of the bitmap. Following common practice, the \abbr{TDS} segregates fonts with different device types into separate directories. See \path|modes.mf| in Appendix~\ref{sec:Related references} for recommended mode names. Some printers operate at more than one resolution (e.g., at 300\,dpi and 600\,dpi), but each such resolution will necessarily have a different mode name. Nothing further is needed, since implicit in the \TeX{} system is the assumption of a single target resolution. Two naming strategies are commonly used to identify the resolution of bitmap font files. On systems that allow long filenames (and in the original \MF{} program itself), the resolution is included in the filename (e.g., \path|cmr10.300pk|). On systems which do not support long filenames, fonts are generally segregated into directories by resolution (e.g., \path|dpi300/cmr10.pk|). Because the \abbr{TDS} cannot require long filenames, we must use the latter scheme for naming fonts. So we have two more subdirectory levels under \path|pk| and \path|gf|: \begin{ttdisplay} texmf/fonts/pk/\replaceable{mode}/\replaceable{supplier}/\replaceable{typeface}/dpi\replaceable{nnn}/ texmf/fonts/gf/\replaceable{mode}/\replaceable{supplier}/\replaceable{typeface}/dpi\replaceable{nnn}/ \end{ttdisplay} \begin{description} \item[\replaceable{mode}] is a name which identifies the device type (examples: \path|cx|, \path|gsftopk|, \path|ljfour|). Usually, this is the name of the \MF{} mode used to build the \path|PK| file. For fonts rendered as bitmaps by a program that does not distinguish between different output devices, the \replaceable{mode} name shall be that of the program (e.g., \path|ps2pk|, \path|gsftopk|). The \replaceable{mode} level shall never be omitted, even only a single mode happens to be in use at a given time. \item[\path|dpi|\replaceable{nnn}] specifies the resolution of the font (examples: \path|dpi300|, \path|dpi329|). `\literal{dpi}' stands for dots per inch, i.e., pixels per inch. We recognize that pixels per millimeter is used in many parts of the world, but dpi is too traditional in the \TeX{} world to consider changing now. The integer \replaceable{nnn} is to be calculated as if using \MF{} arithmetic and then rounded; i.e., it is the integer \MF{} uses in its output \path|gf| filename. We recognize small differences in the resolution are a common cause of frustration among users, however, and recommend implementors follow the level~0 \abbr{DVI} driver standard (see Appendix~\ref{sec:Related references}) in bitmap font searches by allowing a fuzz of $\pm0.2$\% (with a minimum of $1$) in the \replaceable{dpi}. \end{description} Implementations may provide extensions to the basic naming scheme, such as long filenames (as in the original \MF{}) and font library files (as in em\TeX{}'s \path|.fli| files), provided that the basic scheme is also supported. \subsubsection{Valid font bitmaps} \label{sec:Valid font bitmaps} The \abbr{TWG} recognizes that the use of short filenames has many disadvantages. The most vexing is that it results in the creation of dozens of different files with the same name. At a typical site, \path|cmr10.pk| will be the filename for Computer Modern Roman 10\,pt at 5--10 magnifications for 2--3 modes. (Section~\ref{sec:Duplicate filenames} discusses duplicate filenames in general.) To minimize this problem, we strongly recommend that \path|PK| files contain enough information to identify precisely how they were created: at least the mode, base resolution, and magnification used to create the font. This information is easy to supply: a simple addition to the local modes used for building the fonts with \MF{} will automatically provide the required information. If you have been using a local modes file derived from (or that is simply) \path|modes.mf| (see Appendix~\ref{sec:Related references}), the required information is already in your \path|PK| files. If not, a simple addition based on the code found in \path|modes.mf| can be made to your local modes file and the \path|PK| files rebuilt. \subsection{Non-font \MF{} files} \label{sec:Non-font MF files} Most \MF{} input files are font programs or parts of font programs and are thus covered by the previous section. However, a few non-font input files do exist. Such files shall be stored in: \begin{ttdisplay} texmf/metafont/\replaceable{package}/ \end{ttdisplay} \replaceable{package} is the name of a \MF{} package (for example, \path|mfpic|). The \abbr{TDS} reserves the following \replaceable{package} names: \begin{itemize} \item \path|base|, for the standard \MF{} macro files as described in \citetitle{The \MF{}book}, such as \path|plain.mf| and \path|expr.mf|. \item \path|local|, for local additions. See Section~\ref{sec:Local additions}. \item \path|misc|, for \MF{} packages consisting of only a single file (for example, \path|modes.mf|). \end{itemize} \subsection{\MP{}} \label{sec:MetaPost} \MP{} is a picture-drawing language developed by John Hobby, derived from Knuth's \MF{}. Its primary purpose is to output Encapsulated \PS{} instead of bitmaps. \MP{} input files and the support files for \MP{}-related utilities shall be stored in: \begin{ttdisplay} texmf/metapost/\replaceable{package}/ \end{ttdisplay} \replaceable{package} is the name of a \MP{} package. At the present writing none exist, but the \abbr{TWG} thought it prudent to leave room for contributed packages that might be written in the future. The \abbr{TDS} reserves the following \replaceable{package} names: \begin{itemize} \item \path|base|, for the standard \MP{} macro files, such as \path|plain.mp|, \path|mfplain.mp|, \path|boxes.mp|, and \path|graph.mp|. This includes files used by \iniMP{} when dumping mem files containing preloaded macro definitions. \item \path|local|, for local additions. See Section~\ref{sec:Local additions}. \item \path|misc|, for \MP{} packages consisting of only a single file. \item \path|support|, for additional input files required by \MP{} utility programs, including a font map, a character adjustment table, and a subdirectory containing low-level \MP{} programs for rendering some special characters. \end{itemize} \subsection{\BibTeX{}} \label{sec:BibTeX} \BibTeX{}-related files shall be stored in: \begin{ttdisplay} texmf/bibtex/bib/\replaceable{package}/ texmf/bibtex/bst/\replaceable{package}/ \end{ttdisplay} The \path|bib| directory is for \BibTeX{} database (\path|.bib|) files, the \path|bst| directory for style (\path|.bst|) files. \replaceable{package} is the name of a \BibTeX{} package. The \abbr{TDS} reserves the following \replaceable{package} names (the same names are reserved under both \path|bib| and \path|bst|): \begin{itemize} \item \path|base|, for the standard \BibTeX{} databases and styles, such as \path|xampl.bib|, \path|plain.bst|. \item \path|local|, for local additions. See Section~\ref{sec:Local additions}. \item \path|misc|, for \BibTeX{} packages consisting of only a single file. \end{itemize} \subsection{Documentation} \label{sec:Documentation} Most packages come with some form of documentation: user manuals, example files, programming guides, etc. In addition, many independent files not part of a macro or other package describe various aspects of the \TeX{} system. The \abbr{TDS} specifies that these additional documentation files shall be stored in a structure that parallels to some extent the \path|fonts| and \path|tex| directories, as follows: \begin{ttdisplay} texmf/doc/\replaceable{category}/... \end{ttdisplay} \replaceable{category} identifies the general topic of documentation that resides below it; for example, a \TeX{} format name (\path|latex|), program name (\path|bibtex|, \path|tex|), language (\path|french|, \path|german|), or other system components (\path|web|, \path|fonts|). The \abbr{TDS} reserves the following categories: \begin{itemize} \item Within each \replaceable{category} tree for a \TeX{} format, the directory \path|base| is reserved for base documentation distributed by the format's maintainers. \item \path|general|, for standalone documents not specific to any particular program (for example, Joachim Schrod's \citetitle{Components of \TeX{}}). \item \path|help|, for meta-information, such as \abbr{faq}'s, David Jones' macro index, etc. \item \path|html|, for \abbr{html} documents. \item \path|info|, for processed Texinfo documents. (Info files, like anything else, may also be stored outside the \abbr{TDS}, at the installer's option.) \item \path|local|, for local additions. See Section~\ref{sec:Local additions}. \end{itemize} The \path|doc| directory is intended for implementation-independent and operating system-independent documentation files. Implementation-dependent files shall be stored elsewhere, as provided for by the implementation and/or \TeX{} administrator (for example, \abbr{VMS} help files under \path|texmf/vms/help|). The documentation directories may contain \TeX{} sources, \abbr{DVI} files, \PS{} files, text files, example input files, or any other useful documentation format(s). See Section~\ref{sec:Documentation tree summary} for a summary. \newpage \section{Summary} \label{sec:Summary} A skeleton of a \abbr{TDS} \texmf{} directory tree: \begin{tdsSummary} bibtex/ \BibTeX{} input files . bib/ \BibTeX{} databases . . base/ base distribution (e.g., \path|xampl.bib|) . . misc/ single-file databases . / name of a package . bst/ \BibTeX{} style files . . base/ base distribution (e.g., \path|plain.bst|, \path|acm.bst|) . . misc/ single-file styles . / name of a package doc/ see Section~\ref{sec:Documentation} and the summary below fonts/ font-related files . / file type (e.g., \path|pk|) . . / type of output device (for \path|pk| and \path|gf| only) . . . / name of a font supplier (e.g., \path|public|) . . . . / name of a typeface (e.g., \path|cm|) . . . . . dpi/ font resolution (for \path|pk| and \path|gf| only) / \TeX{} implementations, by name (e.g., \path|emtex|) metafont/ \MF{} (non-font) input files . base/ base distribution (e.g., \path|plain.mf|) . misc/ single-file packages (e.g., \path|modes.mf|) . / name of a package (e.g., \path|mfpic|) metapost/ \MP{} input and support files . base/ base distribution (e.g., \path|plain.mp|) . misc/ single-file packages . / name of a package . support/ support files for \MP{}-related utilities mft/ \path|MFT| inputs (e.g., \path|plain.mft|) / \TeX{}-related programs, by name (e.g., \path|dvips|) source/ program source code by name (e.g., \path|latex|, \path|web2c|) tex/ \TeX{} input files . / name of a format (e.g., \path|plain|) . . base/ base distribution for format (e.g., \path|plain.tex|) . . misc/ single-file packages (e.g., \path|webmac.tex|) . . local/ local additions to or local configuration files for \replaceable{format} . . / name of a package (e.g., \path|graphics|, \path|mfnfss|) . generic/ format-independent packages . . hyphen/ hyphenation patterns (e.g., \path|hyphen.tex|) . . images/ image input files (e.g., Encapsulated PostScript) . . misc/ single-file format-independent packages (e.g., \path|null.tex|). . . / name of a package (e.g., \path|babel|) \end{tdsSummary} \newpage \subsection{Documentation tree summary} \label{sec:Documentation tree summary} A skeleton of a \abbr{TDS} directory tree under \path|texmf/doc|: \begin{tdsSummary} ams/ . amsfonts/ \path|amsfonts.faq|, \path|amfndoc| . amslatex/ \path|amslatex.faq|, \path|amsldoc| . amstex/ \path|amsguide|, \path|joyerr| bibtex/ \BibTeX{} . base/ \path|btxdoc.tex| fonts/ . fontname/ \citetitle{Filenames for \TeX{} fonts} . oldgerm/ \path|corkpapr| / name of a \TeX{} format (e.g., \path|generic|, \path|latex|) . base/ for the base distribution . misc/ for contributed single-file package documentation . / for \emphasis{package} general/ across programs, generalities . errata/ \path|errata|, \path|errata[1-8]| . texcomp/ \citetitle{Components of \TeX{}} generic/ for non-format-specific \TeX{} packages . babel/ . german/ \path|germdoc| help/ meta-information . ctan/ info about \abbr{ctan} mirror sites . faq/ \abbr{faq}s of \path|comp.text.tex|, etc. html/ \abbr{html} files info/ \abbr{gnu} Info files, made from Texinfo sources latex/ example of \replaceable{format} . base/ \path|ltnews*|, \path|*guide|, etc. . graphics/ \path|grfguide| / \TeX{}-related programs, by name (examples follow) metafont/ \path|mfbook.tex|, \path|metafont-for-beginners|, etc. metapost/ \path|mpman|, \path|manfig|, etc. tex/ \path|texbook.tex|, \citetitle{A Gentle Introduction to \TeX{}}, etc. web/ \path|webman|, \path|cwebman| \end{tdsSummary} \appendix \section{Unspecified pieces} The \abbr{TDS} cannot address the following aspects of a functioning \TeX{} system: \begin{enumerate} \item The location of executable programs: this is too site-dependent even to recommend a location, let alone require one. A site may place executables outside the \texmf{} tree altogether (e.g., \path|/usr/local/bin|), in a platform-dependent directory within \texmf{}, or elsewhere. \item Upgrading packages when new releases are made: we could find no way of introducing version specifiers into \texmf{} that would do more good than harm, or that would be practical for even a plurality of installations. \item The location of implementation-specific files (e.g., \TeX{} \path|.fmt| files): by their nature, these must be left to the implementor or \TeX{} maintainer. See Section~\ref{sec:Example implementation-specific trees}. \item Precisely when a package or file should be considered ``local'', and where such local files are installed. See Section~\ref{sec:Local additions} for more discussion. \end{enumerate} \subsection{Portable filenames} \label{sec:Portable filenames} The \abbr{TDS} cannot require any particular restriction on filenames in the tree, since the names of many existing \TeX{} files conform to no particular scheme. For the benefit of people who wish to make a portable \TeX{} distribution or installation, however, we outline here the necessary restrictions. The \abbr{TDS} specifications themselves are compatible with these. \abbr{ISO}-9660 is the only universally acceptable file system format for \abbr{CD-ROM}s. A subset thereof meets the stringent limitations of all operating systems in use today. It specifies the following: \begin{itemize-squeeze} \item File and directory names, not including any directory path or extension part, may not exceed eight characters. \item Filenames may have a single extension. Extensions may not exceed three characters. Directory names may not have an extension. \item Names and extensions may consist of \emphasis{only} the characters \literal{A}--\literal{Z}, \literal{0}--\literal{9}, and underscore. Lowercase letters are excluded. (The only common place where mixed-case names occur in the \TeX{} system is in \LaTeX{} font descriptor files, and \LaTeX{} does not rely on case alone to distinguish among these files.) \item A period separates the filename from the extension and is always present, even if the name or extension is missing (e.g., \path|FILENAME.| or \path|.EXT|). \item A version number, ranging from 1--32767, is appended to the file extension, separated by a semicolon (e.g., \path|FILENAME.EXT;1|). \item Only eight directory levels are allowed, including the top-level (mounted) directory (see Section~\ref{sec:Rooting the tree}). Thus, the deepest valid \abbr{ISO}-9660 path is: \begin{ttdisplay} texmf/L2/L3/L4/L5/L6/L7/L8/FOO.BAR;1 1 2 3 4 5 6 7 8 \end{ttdisplay} The deepest \abbr{TDS} path needs only seven levels: \begin{ttdisplay} texmf/fonts/pk/cx/public/cm/dpi300/cmr10.pk 1 2 3 4 5 6 7 \end{ttdisplay} \end{itemize-squeeze} Some systems display a modified format of \abbr{ISO}-9660 names, mapping alphabetic characters to lowercase, removing version numbers and trailing periods, etc. \section{Implementation issues} We believe that the \abbr{TDS} can bring a great deal of order to the current anarchic state of many \TeX{} installations. In addition, by providing a common frame of reference, it will ease the burden of documenting administrative tasks. Finally, it is a necessary part of any reasonable system of true ``drop-in'' distribution packages for \TeX{}. \subsection{Adoption of the \abbr{TDS}} We recognize that adoption of \abbr{TDS} will not be immediate or universal. Most \TeX{} administrators will not be inclined to make the switch until: \begin{itemize-squeeze} \item Clear and demonstrable benefits can be shown for the \abbr{TDS}. \item \abbr{TDS}-compliant versions of all key programs are available in ported, well-tested forms. \item A ``settling'' period has taken place, to flush out problems. The public release of this document is the first step in this process. \end{itemize-squeeze} Consequently, most of the first trials of the \abbr{TDS} will be made by members of the \abbr{TDS} committee and/or developers of \TeX{}-related software. Indeed, some of this has taken place during the course of our deliberations (see Appendix~\ref{sec:Related references} for a sample tree available electronically). They will certainly result in the production of a substantial number of \abbr{TDS}-compliant packages. Once installable forms of key \abbr{TDS}-compliant packages are more widespread, some \TeX{} administrators will set up \abbr{TDS}-compliant trees, possibly in parallel to existing production directories. This testing will likely flush out problems that were not obvious in the confined settings of the developers' sites; for example, it should help to resolve OS and package dependencies, package interdependencies, and other details not addressed by this \abbr{TDS} version. After most of the dust has settled, hopefully even conservative \TeX{} administrators will begin to adopt the \abbr{TDS}. Eventually, most \TeX{} sites will have adopted the common structure, and most packages will be readily available in \abbr{TDS}-compliant form. We believe that this process will occur relatively quickly. The \abbr{TDS} committee spans a wide range of interests in the \TeX{} community. Consequently, we believe that most of the key issues involved in defining a workable \abbr{TDS} definition have been covered, often in detail. \TeX{} developers have been consulted about implementation issues, and have been trying out the \abbr{TDS} arrangement. Thus, we hope for few surprises as implementations mature. Finally, there are several (current or prospective) publishers of \TeX{} \abbr{CD-ROM}s. These publishers are highly motivated to work out details of \abbr{TDS} implementation, and their products will provide inexpensive and convenient ways for experimentally-minded \TeX{} administrators to experiment with the \abbr{TDS}. Efforts are under way to set up a ``\abbr{TDS} Registry'' that will coordinate assignment of \abbr{TDS}-compliant directory names and provide a definitive database of \abbr{TDS}-compliant software distributions. (Perhaps this could also serve many sites as the definition of when a package is local.) For now, distribution through \abbr{CTAN} serves as an imprecise registry. \subsection{More on subdirectory searching} \label{sec:More on subdirectory searching} Recursive subdirectory searching is the ability to specify a search not only of a specified directory \replaceable{d}, but recursively of all directories below \replaceable{d}. Since the \abbr{TDS} specifies precise locations for most files, with no extra levels of subdirectories allowed, true recursive searching is not actually required for a \abbr{TDS}-compliant implementation. We do, however, strongly recommend recursive searching as the most user-friendly and natural approach to the problem, rather than convoluted methods to specify paths without recursion. This feature is already supported by many implementations of \TeX{} and companion utilities, for example \abbr{DECUS} \TeX{} for \abbr{VMS}, \application{Dvips(k)}, \application{em\TeX{}} (and its drivers), \application{PubliC \TeX{}}, \application{Web2c}, \application{Xdvi(k)}, and \application{Y\&Y\TeX{}}. Even if your \TeX{} implementation does not directly support subdirectory searching, you may find it useful to adopt the structure if you do not use many fonts or packages. For instance, if you only use Computer Modern and \abbr{ams} fonts, it would be feasible to store them in the \abbr{TDS} layout and list the directories individually in configuration files or environment variables. The \abbr{TWG} recognizes that subdirectory searching places an extra burden on the system and may be the source of performance bottlenecks, particularly on slower machines. Nevertheless, we feel that subdirectory searching is imperative for a well-organized \abbr{TDS}, for the reasons stated in Section~\ref{sec:Subdirectory searching}. Implementors are encouraged to provide enhancements to the basic principle of subdirectory searching to avoid performance problems, e.g., the use of a filename cache (this can be as simple as a recursive directory listing) that is consulted before disk searching begins. If a match is found in the database, subdirectory searching is not required, and performance is thus independent of the number of subdirectories present on the system. Different implementations specify subdirectory searching differently. In the interest of typographic clarity, the examples here do not use the \replaceable{replaceable} font. \begin{description-squeeze} \item[\application{Dvips}:] via a separate \systemitem{ENVIRONVAR}{TEXFONTS\_SUBDIR} environment variable. \item[\application{em\TeX{}}:] \path|t:\subdir!!|; \path|t:\subdir!| for a single level of searching. \item[\application{Kpathsea}:] \path|texmf/subdir//| \item[\abbr{VMS}:] \path|texmf:[subdir...]| \item[\application{Xdvi} (patchlevel 20):] \path|texmf/subdir/**|; \path|texmf/subdir/*| for a single level of searching. Patchlevel 50 and above support the \path|//| notation. \item[\application{Y\&Y \TeX{}}:] \path|t:/subdir//| or \path|t:\subdir\\|. \end{description-squeeze} \subsection{Example implementation-specific trees} \label{sec:Example implementation-specific trees} The \abbr{TDS} cannot specify a precise location for implementation-specific files, such as \path|texmf/ini|, because a site may have multiple \TeX{} implementations. Nevertheless, for informative purposes, we provide here the default locations for some implementations. Please contact us with additions or corrections. These paths are not definitive, may not match anything at your site, and may change without warning. We recommend all implementations have default search paths that start with the current directory (e.g., `\path|.|'). Allowing users to include the parent directory (e.g., `\path|..|') is also helpful. \subsubsection{AmiWeb2C 2.0} (Email \email|scherer@physik.rwth-aachen.de| to contact the maintainer of this implementation.) The natural choice for the root \abbr{TDS} directory on the Amiga is \path|TeXMF:|, either the name of a hard disk partition or an assignment to a specific location on your disk. In addition to Kpathsea's \path|//| notation you may start recursive path search with \path|\replaceable{DEVICE}:/|, e.g., \path|TeXMF:/|. Binaries coming with the AmiWeb2C distribution are assumed to be installed in the \abbr{TDS} hierarchy at \path|TeXMF:bin/web2c/| to distinguish them from \abbr{DVI} drivers from other sources. (For example, Pas\TeX{}'s \application{ShowDVI} and \application{DVIprint} drivers should be installed at \path|TeXMF:bin/pastex/|. The respective configuration files can be placed in \path|TeXMF:pastex/config/| and the assignment \path|TeX:| should point to \path|TeXMF:pastex/|.) All implementation-dependent \TeX{} system files are stored in \path|TeXMF:web2c/| extending the form used by Web2c~7.0: \begin{tdsSummary} TeXMF: \abbr{TDS} root (also \path|ls-R| and \path|MakeTeXls-R|) . web2c/ configuration file \path|texmf.cnf| . . bases/ \MF{} bases, separated by name, e.g., . . . plain/ the ``plain'' base . . formats/ \TeX{} formats, separated by name, e.g., . . . e-plain/ the plain format for ``extended \TeX{}'' . . . latex/ the \LaTeX{} format . . . plain/ the plain \TeX{} format . . mems/ \MP\ memory files, separated by name, e.g., . . . mfplain/ the ``plain mem'' extended for \MF{} input . . . plain/ the ``plain'' memory file . . pool/ pool files for \TeX{}, \MF{}, and \MP{} . . rexx/ \path|MakeMPX.rexx|, \path|CallMF| \end{tdsSummary} Documentation files in AmigaGuide format should be stored at \path|TeXMF:doc/guide/| similar to \path|TeXMF:doc/info/|. \subsubsection{Public \abbr{DECUS} \TeX{}} If another \abbr{VMS} implementation besides Public \abbr{DECUS} \TeX{} appears, the top level implementation directory name will be modified to something more specific (e.g., \path|vms_decus|). \begin{tdsSummary} texmf/ . vms/ \abbr{VMS} implementation specific files . . exe/ end-user commands . . . common/ command procedures, command definition files, etc. . . . axp/ binary executables for Alpha \abbr{AXP} . . . vax/ binary executables for \abbr{VAX} . . formats/ pool files, formats, bases . . help/ \abbr{VMS} help library, and miscellaneous help sources . . mgr/ command procedures, programs, docs, etc., for system management \end{tdsSummary} \subsubsection{Web2c 7.0} All implementation-dependent \TeX{} system files (\path|.pool|, \path|.fmt|, \path|.base|, \path|.mem|) are stored by default directly in \path|texmf/web2c|. The configuration file \path|texmf.cnf| and various subsidiary \path|MakeTeX...| scripts used as subroutines are also stored there. Non-\TeX{} specific files are stored following the \abbr{GNU} coding standards. Given a root directory \replaceable{prefix} (\path|/usr/local| by default), we have default locations as follows: \begin{tdsSummary} / installation root (\path|/usr/local| by default) . bin/ executables . man/ man pages . info/ info files . lib/ libraries (\path|libkpathsea.*|) . share/ architecture-independent files . . texmf/ \abbr{TDS} root . . . web2c/ implementation-dependent files (\path|.pool|, \path|.fmt|, \path|texmf.cnf|, etc.) \end{tdsSummary} See \url|ftp://ftp.gnu.ai.mit.edu/pub/gnu/standards.text| for the rationale behind and descriptions of this arrangement. A site may of course override these defaults; for example, it may put everything under a single directory such as \path|/usr/local/texmf|. \section{Is there a better way?} Defining the \abbr{TDS} required many compromises. Both the overall structure and the details of the individual directories were arrived at by finding common ground among many opinions. The driving forces were feasibility (in terms of what could technically be done and what could reasonably be expected from developers) and regularity (files grouped together in an arrangement that ``made sense''). Some interesting ideas could not be applied due to implementations lacking the necessary support: \begin{itemize} \item Path searching control at the \TeX{} level. If documents could restrict subdirectory searching to a subdirectory via some portable syntax in file names, restrictions on uniqueness of filenames could be relaxed considerably (with the cooperation of the formats), and the \TeX{} search path would not need to depend on the format. \item Multiple logical \texmf{} trees. For example, a site might have one (read-only) location for stable files, and a different (writable) location for dynamically-created fonts or other files. It would be reasonable for two such trees to be logically merged when searching. \end{itemize} \subsection{Macro structure} The \abbr{TWG} settled on the \replaceable{format}\path|/|\replaceable{package} arrangement after long discussion about how best to arrange the files. The primary alternative to this arrangement was a scheme which reversed the order of these directories: \replaceable{package}\path|/|\replaceable{format}. This reversed arrangement has a strong appeal: it keeps all of the files related to a particular package in a single place. The arrangement actually adopted tends to spread files out into two or three places (macros, documentation, and fonts, for example, are spread into different sections of the tree right at the top level). Nevertheless, the \replaceable{format}\path|/|\replaceable{package} structure won for a couple of reasons: \begin{itemize-squeeze} \item It is closer to current practice; in fact, several members of the \abbr{TWG} have already implemented the \abbr{TDS} hierarchy. The alternative is not in use at any known site, and the \abbr{TWG} felt it wrong to mandate something with which there is no practical experience. \item The alternative arrangement increases the number of top-level directories, so the files that must be found using subdirectory searching are spread out in a wide, shallow tree. This could have a profound impact on the efficiency of subdirectory searching. \end{itemize-squeeze} \subsection{Font structure} The \abbr{TWG} struggled more with the font directory structure than anything else. This is not surprising; the need to use the proliferation of PostScript fonts with \TeX{} is what made the previous arrangement with all files in a single directory untenable, and therefore what initiated the \abbr{TDS} effort. \subsubsection{Font file type location} We considered the supplier-first arrangement in use at many sites: \begin{ttdisplay} texmf/fonts/\replaceable{supplier}/\replaceable{typeface}/\replaceable{type}/ \end{ttdisplay} This improves the maintainability of the font tree, since all files comprising a given typeface are in one place, but unless all the programs that search this tree employ some form of caching, there are serious performance concerns. For example, in order to find a \path|TFM| file, the simplest implementation would require \TeX{} to search through all the directories that contain \path|PK| files in all modes and at all resolutions. In the end, a poll of developers revealed considerable resistance to implementing sufficient caching mechanisms, so this arrangement was abandoned. The \abbr{TDS} arrangement allows the search tree to be restricted to the correct type of file, at least. Concerns about efficiency remain, but there seems to be no more we can do without abandoning subdirectory searching entirely. We also considered segregating all font-related files strictly by file type, so that \MF{} sources would be in a directory \path|texmf/fonts/mf|, property list files in \path|texmf/fonts/pl|, the various forms of Type~1 fonts separated, and so on. Although more blindly consistent, we felt that the drawback of more complicated path constructions outweighed this. The \abbr{TDS} merges file types (\path|mf| and \path|pl| under \path|source|, \path|pfa| and \path|pfb| and \path|gsf| under \path|type1|) where beneficial. \subsubsection{Mode and resolution location} We considered having the \path|mode| at the bottom of the font tree: \begin{ttdisplay} texmf/fonts/pk/\replaceable{supplier}/\replaceable{typeface}/\replaceable{mode}/\replaceable{dpi}/ \end{ttdisplay} In this case, however, it is difficult to limit subdirectory searching to the mode required for a particular device. We then considered moving the \path|dpi|\replaceable{nnn} up to below the mode: \begin{ttdisplay} texmf/fonts/pk/\replaceable{mode}/\replaceable{dpi}/\replaceable{supplier}/\replaceable{typeface}/ \end{ttdisplay} But then it is not feasible to omit the \path|dpi|\replaceable{nnn} level altogether on systems which can and do choose to use long filenames. \subsubsection{Modeless bitmaps} The \abbr{TDS} specifies using utility names as mode names for those utilities which generate bitmaps, e.g., \path|texmf/fonts/pk/gsftopk/|. An alternative was to introduce a single directory \path|modeless/| below which all such directories could be gathered. This has the considerable advantage of not requiring each such directory name to be listed in a search path. But it has disadvantages, too: it would use the last available directory level, preventing any future expansions; and it would put \path|PK| files at different depths in the tree, possibly hindering search strategies and certainly a likely source of confusion. We decided to stay with existing practice and keep the utility name at the same level as the mode names. We are making an implicit assumption that \MF{} is the only program producing mode-dependent bitmaps. If this becomes false we could add an abbreviation for the program to mode names, as in \path|mfcx| vs.\ \path|xyzcx| for a hypothetical program \application{Xyz}, or we could at that time add an additional program name level uniformly to the tree. For our present purposes, it seems more important to concisely represent the current situation than to take account of hypothetical possibilities that may never be realized. \subsection{Documentation structure} We considered placing additional documentation files in the same directory as the source files for the packages, but we felt that users should be able to find documentation separately from sources, since most users have no interest in sources. We hope that a separate, but parallel, structure for documentation would (1)~keep the documentation together and (2)~make it as straightforward as possible for users to find the particular documentation they were after. \section{Related references} \label{sec:Related references} This appendix gives pointers to related files and other documents. In this document, \CTAN: means the root of an anonymous ftp \abbr{ctan} tree. This is both a host name and a directory name. For example: \begin{ttdisplay} \url|ftp://ftp.dante.de/tex-archive| \url|ftp://ftp.tex.ac.uk/tex-archive| \end{ttdisplay} Finger \path|ctan@ftp.tug.org| for a complete list of \abbr{ctan} sites; there are mirrors worldwide. Here are the references: \begin{itemize-squeeze} \item The \abbr{TDS} mailing list archives can be retrieved via ftp from \url|ftp://ftp.tug.org/mail/archives/twg-tds/| and \url|ftp://vms.rhbnc.ac.uk/archives/twg.tds.*|. \item A sample \abbr{TDS} tree: \CTAN:\path|tds|. \item A collection of \BibTeX{} databases and styles: \url|ftp://ftp.math.utah.edu/pub/tex/bib|. \item \citetitle{Components of \TeX{}} by Joachim Schrod: \CTAN:\path|documentation/components-of-TeX|. \item The level~0 \abbr{DVI} driver standard: \CTAN:\path|dviware/driv-standard/level-0|. \item \citetitle{Filenames for \TeX{} fonts}: \CTAN:\path|documentation/fontname|. This distribution includes recommended supplier and typeface names. \item \abbr{ISO}-9660 \abbr{CD-ROM} file system standard: \url|http://www.iso.ch/cate/cat.html|. \item A complete set of \MF{} modes: \CTAN:\path|fonts/modes/modes.mf|. This file includes recommended mode names. \end{itemize-squeeze} \section{Contributors} The \abbr{TWG} had no formal meetings; electronic mail was the primary communication medium. Sebastian Rahtz is the \TeX{} Users Group Technical Council liaison. Norman Walsh is the committee chair. Original contributors: \begin{tabbing} \hspace{.25\linewidth} \= \hspace{.25\linewidth} \= \hspace{.25\linewidth} \= \hspace{.25\linewidth} \kill barbara beeton \> Karl Berry \> Vicki Brown \> David Carlisle \\ Thomas Esser \> Alan Jeffrey \> J\"org Knappen \> Pierre MacKay \\ Rich Morin \> Sebastian Rahtz \> Joachim Schrod \> Christian Spieler \\ Elizabeth Tachikawa \> Philip Taylor \> Ulrik Vieth \> Paul Vojta \\ Norman Walsh \\ \end{tabbing} Additional contributors: \begin{tabbing} \hspace{.25\linewidth} \= \hspace{.25\linewidth} \= \hspace{.25\linewidth} \= \hspace{.25\linewidth} \kill David Aspinall \> Nelson Beebe \> Harriet Borton \> Bart Childs \\ Damian Cugley \> Alan Dunwell \> Michael Ferguson \> Erik Frambach \\ Bernard Gaulle \> Jeffrey Gealow \> George Greenwade \> Thomas Herter \\ Berthold Horn \> Charles Karney \> David Kastrup \> David Kellerman \\ Wonkoo Kim \> Richard Kinch \> Robin Kirkham \> Alex Kok \\ Eberhard Mattes \> Bob Morris \> Lenny Muellner \> Oren Patashnik \\ David Rhead \> Andreas Scherer \> Mark Sinke \> Andrew Trevorrow \\ Doug Waud \> Chee-Wai Yeung \\ \end{tabbing} \end{document}