Please file bugs for problems/feature requests.
Building from trunk
Development is done on Launchpad. To check out the trunk branch you will need to install Bazaar.
Building LightDM from trunk:
bzr branch lp:lightdm cd lightdm ./autogen.sh make make install
bzr branch lp:lightdm my-branch-name cd my-branch-name (make changes) bzr commit bzr push lp:~my-lp-username/lightdm/my-branch-name
Then go to https://code.launchpad.net/~my-lp-username/lightdm/my-branch-name and select "Propose for merging". Your merge proposal will be reviewed by the LightDM development team which often requires some changes to be made by you. You should push your updates to the same branch:
bzr commit bzr push
Once accepted your proposal will be merged by us into the LightDM trunk and be in the next release. Congratulations!
For API documentation either install your distribution provided liblightdm development packages or see online documentation.
You can test greeters either by installing them or running
lightdm --test-mode which allows you to run LightDM inside your session using Xephyr.