This is a detailed document (and associated presentation) describing http2, the background, concepts, protocol and something about existing implementations and what the future might hold.
See http://daniel.haxx.se/http2/ for the canonical home for this project where there's also a more friendly PDF format of this document available. I hope to host and announce updates to this document there.
The document is distributed under the Creative Commons Attribution 4.0 license: http://creativecommons.org/licenses/by/4.0/
I encourage and welcome help and contributions from anyone who may have improvements to offer. As the source is an FODT file, pull requests and diff probably won't work very well so let's try to file issues or send email to firstname.lastname@example.org with your suggestions!