HTTP Archive : The HTTP Archive tracks how the Web is built.
HTML5 Please : Look up HTML5, CSS3, etc features, know if they are ready for use, and if so find out how you should use them – with polyfills, fallbacks or as they
I call this system "Semantic Versioning." Under this scheme, version numbers and the way they change convey meaning about the underlying code and what has been modified from one version to the next.