lua

Polycode. Looks like something like Processing for C++ and Lua - so it's actually a C++ library for creative projects (2D/3D), but at the same time there is a Lua-based scripting layer with which you can program directly with the same APIs. Sounds a bit similar to Cinder, except that there is no scripting solution included, but only a C++ library.

Lightroom Developer Center. Since I want to take a closer look at this again soon, maybe I will create my own plugin for easy sync to WordPress after all. And Lua is not such a terrible language.

Python Package Index : lupa 0.18. Brings LuaJIT2 and Python together, so that you can access Lua scripts from Python, which are then compiled by LuaJIT.

Because I just wrote about Lua: probablycorey's wax provides an Objective-C bridge to Lua, specifically for iOS devices. So you can write iPhone or iPad apps with Lua.

LÖVE - Free 2D Game Engine - in Lua. And it's available for Mac as a Universal Binary. Screenshots look quite nice.