My latest hobby project is web site www.stxmat.dk featuring a series of mathematics videos.
The videos are hosted on YouTube so I wrote a little script in Racket that generates one page for each video. So far I am quite pleased with the result.
In order for the result to look somewhat decent I bought a HTML/CSS design. Thus my usual approach of building web sites representing XHTML as S-expressions were a inconvenient.
Luckily I fell over the new (at least to me) templating library in Racket. It is is easy to use and well thought out.