Editing TeX (section)

==Distributions and extensions==
TeX is usually provided in the form of an easy-to-install bundle of TeX itself along with [[Metafont]] and all the necessary fonts, documents formats, and utilities needed to use the typesetting system. On UNIX-compatible systems, including [[Linux]] and [[Apple, Inc.|Apple]] [[macOS]], TeX is distributed as part of the larger [[TeX Live]] distribution. (Prior to TeX Live, the [[teTeX]] distribution was the de facto standard on UNIX-compatible systems.) On [[Microsoft Windows]], there is the [[MiKTeX]] distribution (enhanced by proTeXt) and the Microsoft Windows version of TeX Live.

Several document processing systems are based on TeX, notably [[jadeTeX]], which uses TeX as a backend for printing from [[James Clark (XML expert)|James Clark]]'s [[Document Style Semantics and Specification Language|DSSSL Engine]], the [[Arbortext]] publishing system, and [[Texinfo]], the GNU documentation processing system. TeX has been the official typesetting package for the GNU operating system since 1984.

Numerous extensions and companion programs for TeX exist, among them [[BibTeX]] for bibliographies (distributed with LaTeX); pdfTeX, a TeX-compatible engine which can directly produce PDF output (as well as continuing to support the original DVI output); [[XeTeX]], a TeX-compatible engine that supports [[Unicode]] and [[OpenType]]; and [[LuaTeX]], a Unicode-aware extension to TeX that includes a Lua runtime with extensive hooks into the underlying TeX routines and algorithms. Most TeX extensions are available for free from [[CTAN]], the Comprehensive TeX Archive Network.

===Editors===
{{See also|Comparison of TeX editors}}

There are a variety of [[:Category:TeX editors|editors designed to work with TeX]]:

# The [[GNU TeXmacs|TeXmacs]] text editor is a [[WYSIWYG]]-[[WYSIWYM]] scientific text editor, inspired by both TeX and [[Emacs]]. It uses Knuth's fonts and can generate TeX output.
#[[Overleaf]] is a partial-WYSIWYG, online editor that provides a cloud-based solution to TeX along with additional features in real-time collaborative editing.
# [[LyX]] is a [[WYSIWYM]] document processor which runs on a variety of platforms including: 
## [[Linux]], 
## [[Microsoft Windows]] (newer versions require Windows 2000 or later) 
## Apple [[macOS]] (using a non-native [[Qt (toolkit)|Qt]] front-end). 
# [[TeXShop]] (for macOS), [[TeXworks]] (for Linux, macOS and Windows) and [[WinShell]] (for Windows) are similar tools and provide an integrated development environment (IDE) for working with LaTeX or TeX. For [[KDE]]/Qt, [[Kile]] provides such an IDE. 
# [[Texmaker]] is the Pure Qt equivalent of Kile, with a user interface that is nearly the same as Kile's.
# [[TeXstudio]] is an open-source fork (2009) of [[Texmaker]] that offers a different approach to configurability and features. Free downloadable binaries are provided for Windows, Linux, macOS, OS/2, and FreeBSD.
# [[GNU Emacs]] has various built-in and third-party packages with support for TeX, the major one being [[AUCTeX]]. 
# [[Visual Studio Code]].  A notable extension is LaTeX Workshop
# For [[Vim (text editor)|Vim]], possible plugins include Vim-LaTeX Suite,<ref>{{Citation | title = Vim-LaTex | publisher = SourceForge | url = http://vim-latex.sourceforge.net/ |url-status=live |archive-url=https://web.archive.org/web/20240308132826/https://vim-latex.sourceforge.net/ |archive-date= Mar 8, 2024 }}</ref> Automatic TeX,<ref>{{Citation | title = Automatic TeX plugin | url = https://launchpad.net/automatictexplugin | publisher = Launch pad }} {{Dead link|date=June 2018 |bot=InternetArchiveBot |fix-attempted=no }}</ref> and TeX-9.<ref>{{Citation | title = TeX-9 | url = http://www.vim.org/scripts/script.php?script_id=3508 | publisher = Vim.org}}</ref> 
# For [[Apache OpenOffice]] and [[LibreOffice]], iMath and TexMaths extensions can provide mathematical TeX typesetting.<ref>{{Citation | title = TexMaths Homepage | publisher = free.fr | url = http://roland65.free.fr/texmaths/}}</ref><ref>{{Citation | title = iMath | publisher = SourceForge | url = https://ooo-imath.sourceforge.io/wiki/index.php/Main_Page}}</ref>
# For [[MediaWiki]], the [[mw:Extension:Math|Math extension]] provides mathematical TeX typesetting, but the code needs to be surrounded by <code><math></code> tag.

===Licence===
Donald Knuth has indicated several times<ref>{{cite journal |last1=Knuth |first1=Donald E. |date=1986 |title=Remarks to Celebrate the Publication of Computers & Typesetting |url=https://tug.org/TUGboat/tb07-2/tb15knut.pdf |journal=TUGboat |volume=7 |issue=2 |pages=95–98 |access-date=6 December 2024}}</ref><ref>{{cite journal |last1=Knuth |first1=Donald E. |date=1990 |title=The Future of TeX and METAFONT |url=https://www.tug.org/TUGboat/tb11-4/tb30knut.pdf |journal=TUGboat |volume=11 |issue=4 |page=489 |access-date=6 December 2024}}</ref><ref>{{cite web |url=https://www.kyotoprize.org/wp-content/uploads/2019/07/1996_A.pdf |title=Digital Typography: 1996 Kyoto Prize Lecture |last=Knuth |first=Donald Ervin |publisher=The Inamori Foundation |date=November 1, 1997 |website=Kyoto Prize |access-date=December 6, 2024}}</ref><ref name="DigitalTypography">{{cite book | last=Knuth | first=Donald E. | title=Digital Typography | publisher=Center for the Study of Language and Information Publications | publication-place=Stanford, Calif | date=1999 | isbn=978-1-57586-010-7 }}</ref> that the source code of TeX has been placed into the "[[public domain]]", and he strongly encourages modifications or experimentations with this source code. However, since Knuth highly values the reproducibility of the output of all versions of TeX, any changed version must not be called TeX, or anything confusingly similar. To enforce this rule, any implementation of the system must pass a test suite called the TRIP test<ref>{{Citation |url=ftp://tug.ctan.org/pub/tex-archive/systems/knuth/dist/tex/trip.tex |title=CTAN |contribution=Trip |type=source code |archive-url=https://web.archive.org/web/20210612084428/ftp://tug.ctan.org/pub/tex-archive/systems/knuth/dist/tex/trip.tex |archive-date=2021-06-12 |url-status=dead |format=TeX}}</ref> before being allowed to be called TeX. The question of licence is somewhat confused by the statements included at the beginning of the TeX source code,<ref>{{Citation |first=Donald E |last=Knuth |title=TeX: The Program |series=Computers and Typesetting |volume=B |place=Reading, MA |publisher=Addison-Wesley |year=1986 |isbn=0-201-13437-3 |url-access=registration |url=https://archive.org/details/texprogram00knut}}</ref> which indicate that "all rights are reserved. Copying of this file is authorized only if&nbsp;... you make absolutely no changes to your copy". This restriction should be interpreted as a prohibition to change the source code ''as long as the file is called tex.web''. The copyright note at the beginning of tex.web (and mf.web) was changed in 2021 to explicitly state this. This interpretation is confirmed later in the source code when the TRIP test is mentioned ("If this program is changed, the resulting system should not be called 'TeX{{'"}}).<ref>[https://books.google.com/books?id=PA-Rhb_QSAwC&dq=tex+in+public+domain+knuth&pg=PA227 Open Source: Technology and Policy] by Fadi P. Deek, James A. M. McHugh "Public domain", page 227 (2008)</ref> The [[American Mathematical Society]] tried in the early 1980s to claim a [[trademark]] for TeX. This was rejected because at the time "TEX" (all caps) was registered by [[Honeywell]] for the "Text EXecutive" text processing system.{{Citation needed|date=April 2010}}

=== XML publication ===
It is possible to use TeX for automatic generation of sophisticated layout for XML data. The differences in syntax between the two description languages can be overcome with the help of [[TeXML]]. In the context of XML publication, TeX can thus be considered an alternative to [[XSL Formatting Objects|XSL-FO]]. TeX allowed scientific papers in mathematical disciplines to be reduced to relatively small files that could be rendered client-side, allowing fully typeset scientific papers to be exchanged over the early Internet and emerging World Wide Web, even when sending large files was difficult. This paved the way for the creation of repositories of scientific papers such as [[arXiv]], through which papers could be 'published' without an intermediary publisher.<ref>{{cite journal|last1=O'Connell|first1=Heath|title=Physicists Thriving with Paperless Publishing |journal=Hep Lib.web.|year=2002 |volume=6|page=3|arxiv=physics/0007040 }}</ref>