I'm using Squeak to create an entire PDA environment to supplant WinCE, Linux/PDA, or anything else on top of which Squeak can runs. At http://spe.sourceforge.net, there is some information about the project, but admittedly, not much. I'm sick of inconsistent software systems that are impossible to extend, customize and script, so I'm creating my own in Squeak. May not be practical for other people to use it, but in all honesty, I'm most concerned about what I want out of a portable computer.|
When the Dynapad has reached some point of completion, it will have something like you describe- an IDE designed for a small screen, with it's own straight forward GUI API that uses Morphic for display. NewtDevEnv on the Newton also achieves this goal very well, IMO, but falls a little short on account of there being no debugger.