HTML is pretty basic, so for April Fool's Day we decided to give the world a better, more advanced version that would let you do some actually useful stuff in code. We called it HTML11.
We did a series of demos, showing how our imaginary tags would work
We created a site for HTML11 and used it to host our demo videos and code examples. To make it feel more real, we also made it look appropriately undesigned, just like W3C's (the people who write the official HTML specs) site is.