
It was released today under the GNU Affero General Public license, version 3. The announcement was made early this morning on the Launchpad Blog by Developer Karl Fogel.
According to the blog post Canonical had previously announced that they would be holding back two components (codehosting and soyuz), but they changed their minds. All the code is open.
If you need to collaborate with the launchpad team on further development of development related issues the Canonical Launchpad developers will be on IRC in channel #launchpad-dev on irc.freenode.net. For usage issues, #launchpad is still the place, as before.
Feel free to read the announcement at http://blog.launchpad.net/general/launchpad-is-now-open-source