For example EZTV has PHP and lighttpd amongst others displayed at the bottom of the main page.
I can remember coming across a forum post somewhere on the net listing a whole host of these and the actual icon type had a specific name. Any ideas?
They're called web badges (Wikipedia) or buttons:
- Adam Kalsey's button maker
- ButtonBrowser history (another button maker's recently created buttons)
- Microformats wiki buttons
I can't actually find a good comprehensive list, there's gotta be one out there! These were all the rage back in the day :D