GAM is a free, open source command line tool for Google Apps Administrators to manage domain and user settings quickly and easily.
You can download the current GAM release from the GitHub Releases page.
The GAM documentation is hosted in the GitHub Wiki
The GAM mailing list / discussion group is hosted on Google Groups. You can join the list and interact via email, or just post from the web itself.
The official GAM source repository is on GitHub in the master branch.
GAM is maintained by Jay Lee.