also, when youve mastered one GUI toolkit its fairly straightforward to pick up others

Having used a variety of GUI toolkits under different OS (AWT, .NET, MFC, Qt, OpenGL). In my opinion the most important thing to have is a good GUI builder tool. Most of the IDEs these days come with GUI building tools and also the GUI tools can for the most part be plugged into IDE. That said, I have found Qt quit good when plugged into Eclipse.

regarding a 'History of the UNIX kernel' class, check out http://bitsavers.org/pdf/bellLabs/unix/ it has some interesting documents about the and unix kernel and some of the listings are being used as part of the current effort to resurrect the very early unix (ie v1 etc) also theres always lions commentary to be found on the net at http://www.lemis.com/grog/Documentation/Lions/

It would be nice to have a tar of the whole lot, theres a LOT of files in there