HTML5 Boilerplate - A rock-solid default for HTML5 awesome.
After more than two years in iterative development, you get the best of the best practices baked in: cross-browser normalization, performance optimizations, even optional features like cross-domain ajax and flash. A starter apache .htaccess config file hooks you the eff up with caching rules and preps your site to serve HTML5 video, use @font-face, and get your gzip zipple on.
