TransSkel is a library for simplifying event processing, menu handling, window management etc, all those tedious things that makes Mac programming hard to get into.
When I started programming the Mac, there were two things that took me from a state where it all felt hopeless and just too much to grasp, to a state where I felt comfortable. They were 1) TransSkel (instead of building applications from the bottom and up, or from bigger demos) and 2) Think Pascal (instead of Think C). I wholeheartedly recommend both for anyone who wants a nice and easy path into Mac programming.
TransSkel is a Public Domain library, written by Paul Dubois (original C version), Owen Hartnett (Pascal version) and to some extent myself (update from TransSkel Pascal 2.0 to TransSkel Pascal 2.5).
What you find here, as part of SAT, is just a small subset of TransSkel. For the full Pascal version, look in my ftp archive at ftp.lysator.liu.se/pub/mac/source. For the C version, check out Paul Dubois archive. (Sorry, but the address escapes me for the moment.)