HTML5, has been spruced up with a dedicated logo from its parent organization, the W3C. We'd wax poetic about it, but that job has already been done:
[Thanks, Matt]"It stands strong and true, resilient and universal as the markup you write. It shines as bright and as bold as the forward-thinking, dedicated web developers you are. It's the standard's standard, a pennant for progress. And it certainly doesn't use tables for layout."