Since a few weeks LuaJitTeX is available ¹, which is LuaTeX with Lua replaced by LuaJIT. Binaries are available for various platforms. It is already included in the ConTeXt standalone distribution.
I wonder which sort of documents benefit from using LuaJitTeX? If non-standard fonts are used XeTeX is a good choice, if MetaPost is involved LuaTeX is a good choice, just to give an example.
- What's exactly the use case for LuaJitTeX?
- Does it ever make sense to turn Jit on (in contrast to just using the virtual machine of LuaJitTeX)? The ConTeXt help states:
--jiton jit turned on (in most cases not faster, even slower)and running a small test suggests that it really appears to be slower. I don't know if that is always the case and I wonder if there are any counter examples.
¹ The source code can be obtained with: svn co http://foundry.supelec.fr/svn/luajittex/trunk. The binaries can be found on http://svn.contextgarden.net/suite-bin/tex/.