This site was built using the HTML5 specification and several CSS3 elements - I love learning new things, so while it was a bit of a challenge getting my head around the whole 'sections vs articles' thing it was a lot of fun.
The backend is handled by Wordpress 3 (like 99% of the other websites I've built over the last year), and I can say for certain that I won't be building anything in plain HTML again for a long time!
- Cerys