Right, you don't need to write a parser if you're using ObjectiveC - its baked in. But if you're using Java, or Python sans ObjC, you will need to write one (well, for Java you can use mine). I don't have one in Python though.

FScript is basically smalltalk scripting using ObjectiveC objects. It does math with NSNumbers and supports Blocks (something we miss very much in ObjectiveC).

So you can do something like:

myNSArray do: [:ea | ea doSomethingCool].

Its just smalltalk scripting though - it has no support for making new classes. OTOH, you can pass around FScript Blocks - which are arbitrary code. If you're doing ObjectiveC and you need to provide user scripting, FScript is the bomb.

There's been a nifty hack called FScriptAnywhere that will fiddle an application's framework list to pull in FScript and put an FScript menu item on the menubar. There's also a GUI object inspector/navigator that you can use to dig around in a program. So you can monkey with objects in other people's applications and add new menu commands. Its pretty cool.