Withknown shipped AMP support today in both the open source:

http://stream.withknown.com/2015/self-hosted-known-085-has-left-the-building---with-better

and hosted versions of their sites:

http://known.kevinmarks.com/2015/the-web-succeeded-because-its-open-its-easy-its-agnostic?_t=amp

How do they get added to the partners list on ampproject.org ?