It looks like some Microsoft Windows source code has leaked onto the internet. Oh gee. This didn't sound very remarkable to me, since the source code of rising *nix competitors has long been circulating. But the BBC makes some amusing points:

BBC NEWS | Technology | Q&A: Microsoft source code leaked: "Fourthly, for Microsoft to have this code paraded in public is hugely embarrassing. Not least because the code is littered with profanity and might show that many Microsoft programmers do not do a very good job. In the past independent programmers that have deconstructed other Microsoft applications have been shocked at what they found within the code. Rivals and critics will be able to see exactly how Microsoft staff do their work."