TeX Live [SEP] operating system
TeX Live
TeX Live is a cross-platform, free software distribution for the TeX typesetting system that includes major TeX-related programs, macro packages, and fonts. It is the replacement of its no-longer supported counterpart teTeX.
It is now the default TeX distribution for several Linux distributions such as
openSUSE,
Fedora,
Debian, Ubuntu, 
Termux and Gentoo.
Other Unix operating systems like OpenBSD, FreeBSD and NetBSD have also converted from teTeX to TeX Live.
The project was originally
based on TeX, notably jadeTeX, which uses TeX as a backend for printing from James Clark's 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 bypasses DVI and produces output in PDF, XeTeX, an TeX-compatible engine that supports Unicode and OpenType