Jono Bacon (Ubuntu Community Manager) announced on his blog:-
Some time back we made Launchpad available as Open Source, and we have gone on to see a wonderful and thriving Launchpad development community flourish there.
One component in particular that was not made available as Open Source, was the Canonical Identity Provider which is used by the Launchpad Single Sign On and Ubuntu Single Sign on facilities. I am pleased to announce that we are now able to provide this code under an AGPL3 license. Thanks to Stuart Metcalfe who has been coordinating the technical and licensing work to be able to contribute this change.
You can grab the code from this Launchpad project page.