koen: The psx4all source is such a mess I'd feel sorry for those who have to deal with it. On that note, Unai and Chui are reworking things for psx4all, hopefully from the ground up, and theres the chance they might open source it. If I hear that they do, I'll let you know.
gpSP for the GP2X will be, like the PSP version, very tied to it's hardware. I will see if I can come up with a quick gpSP port to the Zaurus later today, with nothing "hardware specific", and it will most likely use SDL.
So the Zaurus might have a gpSP port very soon, though it will most likely be unofficial for now, since Exophase may not want to go this direction with his application.
I've been trying to get things up and running for the pla ystation emu written from the ground up for handhelds. I'm not the lead on this emu. It is progressing along while I try to manage some of the smaller aspects of things along its way. So far so good.