TeX is a free typesetting system for which many extensions have been developed.^[1]

Languages

ArabTeX – adds support for Hebrew and Arabic alphabets^[2]
FarsiTeX – adds support for Farsi^[3]
Omega (TeX) – extends multilinguality by using the Basic Multilingual Plane of Unicode
XeTeX – uses Unicode, adds additional fonts^[4]
TIPA (software) – supports phonetic characters^[5]
CTeX – Chinese TeX^[6]
MonTeX – Mongolian LaTeX^[7]

Science

AMS-LaTeX and AMS-TeX - classes and packages developed for the American Mathematical Society; extensions of LaTeX and TeX respectively^[8]
CircuiTikZ - adds creation of electrical networks (adds on to TikZ)^[9]
REVTeX - collection of LaTeX macros used for scientific journals^[10]
XyMTeX - supports chemical structure diagrams

MusiXTeX - allows music typesetting
Gregorio - allows typesetting of Gregorian chant
PGF/TikZ - languages that provide vector graphics
PSTricks - allows using PostScript drawings
Texinfo - used for software manuals, can produce both print and Web documentation)

^ "The TeX Frequently Asked Question List". The TeX FAQ. Archived from the original on 21 September 2018. Retrieved 28 September 2018.
^ "ArabTeX Version 3".
^ Esfahbod, Behdad. "The FarsiTeX Project". persian-computing.org. Archived from the original on 28 July 2018. Retrieved 28 September 2018.
^ "XeTeX - TeX Users Group". tug.org. Retrieved 28 September 2018.
^ Fukui, Rei (2004). TIPA Manual (Version 1.3) (PDF). Graduate School of Humanities and Sociology, The University of Tokyo. p. 1.
^ "Welcome to Chinese TeX". Archived from the original on 28 October 2018. Retrieved 27 October 2018.
^ "MonTeX – Mongolian LaTeX". Archived from the original on 28 October 2018. Retrieved 27 October 2018.
^ "American Mathematical Society". Archived from the original on 16 August 2018. Retrieved 28 September 2018.
^ "CircuiTikz - Easy electrical networks | TikZ example". www.texample.net. Archived from the original on 28 September 2018. Retrieved 28 September 2018.
^ "REVTeX Home Page". Physical Review Journals. 19 December 2012. Retrieved 28 September 2018.
^ https://petr.olsak.net/optex/

Macro packages

Alternative TeX engines

Active	LuaTeX pdfTeX XeTeX
Deprecated	Aleph ε-TeX NTS Omega

Distributions

Active	MiKTeX TeX Live MacTeX W32TeX TeXPortal TinyTeX
Deprecated	AmigaTeX fpTeX gwTeX OzTeX PasTeX teTeX

Community