Apple WWDC Summary
I must admit I have not been a long time slashdot.org reader but I feel that I am in a great position to give a general summary of the Rhapsody/MacOS summary, having been at WWDC all week.
The Steve Jobs keynote was confusing to say the least, leaving a lot of Mac developers in utter confusion. It took multiple sessions over several days to clear the OS strategy which I have summarized below:
MacOS X will essentially be Rhapsody but for branding (ie marketing) purposes, the name will remain the same. It was also quite clear that application vendors who have current legacy code gave tremendous resistance to the absolute switch to YellowBox, rendering their current applications effectively dead, which gave rise to Carbon (see below). Rhapsody and MacOS X WILL converge at some future date into a cohesive OS to which most applications should move seamlessly.
YellowBox, Carbon, BlueBox
The YellowBox is a BIG part of MacOS X. It is the Apple recommended development API for all new projects, especially cross platform ones. The way this works under MacOS X is that it is an "application environment", basically a system DLL, as is Carbon and as is the legacy environment (a boxless BlueBox). The Carbon API as stated before will take advantage of the new multi threading, protected memory, etc, while all boxless BlueBox applications will exist in a single process.
BSD support will exist in MacOS X, although hidden from the end user. Sockets will apparently be in there and OpenTransport should make an appearance although probably layered on the socket interface.
I see Rhapsody as a release to help keep the NeXT developers on board since there is a good (relatively speaking) business presence they have built. It will also be a test bed for new technologies for MacOS X.
There is also some really cool low level stuff that can be done for Rhapsody/MacOS X like writing plugins for the VFS and custom memory paging routines.
I trust this clears things up!