I have stopped working on Neutrino. See its page for details.
In 2003, Mac Murrett and I worked on an ill-fated commercial project called NetBuild, which I finally got around to packaging up and releasing as Open Source in early 2005.
For ADHOC/MacHack 19 in 2004, I wrote and presented a paper, "Weaving the Leopard's Pelt: Simulating Fibers on OS X" (PDF):
What if you wanted to port to Mac OS X a platform-independent codebase that makes one crucial assumption: that there is one execution path, and it is controlled by the codebase itself? Not necessarily an unusual assumption for, say, an older Unix or DOS command-line application.
Both Cocoa and Carbon (using RAEL) assume applications will relinquish control for event handling. You could use standard multithreading to handle this, but this session describes an easier way: simulate a "fiber", a manually-managed thread-like mechanism on Windows NT and later, to hand off control to the OS without giving up program flow in the ported codebase.
It tied for best paper.
For MacHack 18 in 2003, I and Mac Murrett wrote and presented a paper about the Membrane library for transitioning between C++ and Objective-C.
We also won third place in the hack contest.
You might also be interested in the list of Cocoa Web sites I put together, or in the applications I've found useful as a Mac developer.
My major Macintosh project for the last few years was MacTADS, Macintosh-hosted developer tools for making TADS text adventure games. I have stopped work on it. Please see that page for more details.