Dito GAM is a free, open source command line tool for Google Apps Administrators to efficiently manage domain and user settings quickly and easily. GAM has support for many features, such as

creating, deleting, and updating users, aliases, groups, organizations, and resource calendars
modifying user email settings such as IMAP, signatures, vacation messages, profile sharing, email forwarding, send as address, labels, and features.
delegating mailboxes and calendars to other users
modifying calendar access rights for users and resource calendars.
auditing user accounts and mailboes
monitoring incoming and outgoing email
generating detailed reports for users, groups, resources, account activity, email clients, and quotas.

Resources

There are a number of GAM resources available via several different websites.

Source Repository

The official GAM source repository is on Github.

Downloads

You can download current and pre-released versions of GAM from the Github Releases page. Final releases are also available on Google Drive

Wiki Documentation

The GAM documentation is currently hosted on Google Code and can be found at the Gam Getting Started Wiki

Mailing List / Discussion group

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.

Author

GAM is maintained by Jay Lee.

THANKS TO

GAM is made possible and maintained by the work of Dito. Who is Dito?

Dito is solely focused on moving organizations to Google's cloud. After hundreds of successful deployments over the last 5 years, we have gained notoriety for our complete understanding of the platform, our change management & training ability, and our rock-star deployment engineers. We are known worldwide as the Google Apps Experts.

Need a Google Apps Expert? Contact Dito, which offers free premium GAM support for domains that sign up through Dito.