I’m in the process of retooling this site with WordPress, a popular open source blog CMS. The code it generates is pretty decent (it validates at least) but as I’m a bit of a stickler when it comes to markup I’ve been hacking and customizing it to get it exactly the way I want it. It’s a good excuse to improve my PHP coding skills, which I’ve been putting off for too long (been having too much fun with JSP, Struts, and JSTL that I use at work I guess).
WordPress still leaves a little to be desired in terms of the markup it generates, with too much hard-coded HTML in files outside of the theme directories. Optimally any markup generated by the application should be customizable so it can be easily changed at the the theme level. That being said, they seem to be on the right track in terms of attempting to separate the markup generation from the application engine, and are making progress with each new release.