Software development; mainly Ada, mainly on Mac OS X.
So far he has written two articles on his blog:
As I’ve just recently bought a MacBook Air, which I’m very pleased with, I plan on keeping an eye on this blog. One of these days I’ll get around to setting up an Ada environment on it, so I can do a little bit of Ada programming even though I’m away from my main workstation.
Finally it might be worth mentioning that Simon is the man behind quite a few interesting projects, as can be seen from glancing at his SourceForge page.