UK TeX FAQ -- question label luatex

### PDFTeX and LuaTeX

As is said elsewhere in these FAQs, development of PDFTeX is “in essence” complete — no new facilities are being developed, since the limitations of the present structure mean that the returns on effort invested are diminishing. The PDFTeX team has announced that no further developments will be added after the release of PDFTeX 1.50.0, which will be the next major release.

In parallel with the running-down of PDFTeX development, development of a new system, LuaTeX is under way. Lua is a script language, designed to offer an interpreter that may be incorporated into other applications. LuaTeX consists of a TeX-like engine with a lua interpreter built into it; the lua interpreter has access to many of the data structures used for typesetting, and the user may also interpolate chunks of lua code into their (La)TeX macros, or as ‘call-backs’ for use when the TeX-like engine does certain operations.

This arrangement offers the prospect of a “semi-soft” typesetting engine: it will have its basic behaviour, but the user gets to redefine functionality if an idea occurs — there will be no need to persuade the world first, and then find a willing developer to work on the sources of of the distribution.

The LuaTeX project is (with monetary support from various sources) pursuing avenues that many of the other current projects have in their sights, notably Unicode character representations and support for OpenType fonts. The intention is to integrate the extensions pioneered by Aleph.

A release of LuaTeX whose functionality is declared (version 0.50) has recently appeared. TeX Live 2008 incorporates an early release of LuaTeX, and the upcoming MiKTeX version 2.8 (no current release date) will probably incorporate LuaTeX. ConTeXt distributions can already make use of LuaTeX.

This question on the Web: http://www.tex.ac.uk/cgi-bin/texfaq2html?label=luatex