Nathan Willis has written an excellent article on LWN.net about Hockeypuck -- a new, AGPL public key server written in Golang with a MongoDB backend, authored by my esteemed colleague, Casey Marshall.
I recently introduced Hockeypuck here, and Casey wrote his own intro here.
Casey presented Hockeypuck at SCALE11x on Sunday, February 24th, 2013. Nathan attended Casey's talk, and published his own review of Hockeypuck. The article is very comprehensive and well written. If you missed Casey's talk, it's an excellent retrospective and a good technical introduction to the project.
Enjoy,
Dustin