Speaking of using other tools for testing and prototyping, there are REPLs available for Cocoa. My personal favorite is Nu[1] with Nutronic[2], though you can

Speaking of using other tools for testing and prototyping, there are REPLs available for Cocoa. My personal favorite is Nu[1] with Nutronic[2], though you can do similar things with MacRuby and PyObjC. [1] http://programming.nu/ http://programming.nu/ [2] http://itfrombit.github.com/nutron/ http://itfrombit.github.com/nutron/