ScrIDE is an OSX based IDE for scripting languages. It was born from the ashes of PyOXIDE (a Python IDE), rewritten to fix some of the underlying weakness in PyOXIDE. Unlike PyOXIDE, it isn't tied to a single version of Python (and its associated extensions) - for that matter, it isn't tied to Python at all. Instead, includes varying degrees of support for Lua, TCL, and Ruby (and is extensible enough that it can allow other languages as well) - Python is just a "first citizen" (and an exemplar for its features, and currently the more advanced features are only available to Python).
