I just noticed that the source to Allegro has been posted by HitMan on OS4Depot. Some time back there was some interest in getting it ported to MorphOS but the bounty went only as far as getting it on OS4. I've looked at the source and it looks plausible to port but since most of the software that uses it is closed-source we might not get many ports out of it. If anybody is still interested I might have a go at it.