WordPress
Written in 2004 and kept as it was, so some of it will have aged.
Not that you’re likely to have noticed, but this blog is now running on WordPress instead of Movable Type. As I become better at PHP programming, I’d like the entire site to be written in it. And, even better, it’s available under the GNU Public License, which means it is free and can be altered as needed. Not very interesting I know, but I have to keep up my computing somehow or I’ll forget how!