Some software builds on LaTeX or is closely related and offers different interesting approaches.
XeTeX extends TeX by Unicode support and modern font technologies for using OpenType and TrueType fonts and Apple Advanced Typography. It natively supports Unicode.
The LaTeX version is called XeLaTeX.
Initially developed for Mac OS X, XeTeX is now available for Windows and Linux/Unix as well. For example, you can use it with TeXworks by choosing XeTeX, XeLaTeX respectively, as typesetng engine
LuaTeX is an extended version of pdfTeX. It uses Lua as its scripting language. The LuaTeX project aims to develop an enhanced TeX version while keeping downward compatibility.
Lua is a ...