LÖVE

Penlight looks cool, so does the polygon clipping lib.

A macro system for Lua:
http://luma.luaforge.net/manual.html

After dabbling in Scheme/Lisp and Io, I've been craving some metaprogramming facilities in Lua. I find myself repeating code that could be abstracted away with macros. Has anyone else looked into this?

jcw wrote: After dabbling in Scheme/Lisp and Io, I've been craving some metaprogramming facilities in Lua. I find myself repeating code that could be abstracted away with macros. Has anyone else looked into this?

You ought to take a look at Metalua.

Others along the same lines include LuaFish (mentions a couple other projects in the post, too), and luaSub, by the Lanes author.

Also:

Luiz has quite a few tools in addition to the polygon clipping binding, available at his page:

Tools