Linux and 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'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 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 There are a variety of editors designed to work with TeX: The 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 Mac OS X (using a non-native Qt front-end). TeXShop (for Mac OS X), TeXworks (for Linux, Mac OS X 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, Mac OS X, 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, possible plugins include Vim-LaTeX Suite, Automatic TeX and TeX-9. For Apache OpenOffice and