The code could definitely do with an overhaul, but in terms of it's functionality and usability, it does pretty well. My thought for mentioning it, was that it may be more worth improving the YaBB code and extending it with any features that might be missing. phpBB already has a big market share and starting from scratch with something like this would be no mean feat.

I started to write my own bulletin board system, but quickly realised that to do it properly would take far too long. YaBB offers all the public facing features I wanted and the admin side isn't too bad to master. In time I may supply patches to improve the codebase, but for the moment it does the job I wanted it to.