I've got a question about a LuaTeX design decision. I'd like to know why LuaTeX embeds Lua in a typesetting program. Perhaps it could instead have extended Lua with a typesetting module. Here's how to embed Lua (in the host program): http://www.lua.org/manual/5.0/manual.html#3 Here's how to extend Lua (with additional 'builtins'): http://www.lua.org/manual/5.0/manual.html#3.16 Here's an example of a Lua extension: http://www.tecgraf.puc-rio.br/~diego/professional/luasocket/ One of the key difference between embed and extend is that Lua socket "is available to any Lua application once it has been properly initialized by the interpreter in use." LuaTeX, because it embeds Lua, is not be similarly available to other Lua applications. -- Jonathan