From a GPO Announcement:
The U.S. Government Publishing Office (GPO) now has an official agency presence on GitHub. Currently, more than 10,000 government users worldwide employ GitHub to collaborate on code, data, and policy. Federal agencies currently using GitHub to make information available about their systems include the Library of Congress, the National Archives and Records Administration, the Smithsonian, and the White House.
In the current digital environment, there is a growing expectation for sharing not only information content stored on digital systems, but for sharing information on how that content is created, processed, stored, and made available to the public.
GPO has established a presence on GitHub to share information about how content is stored and processed on its Federal Digital System FDsys.
Through GitHub, GPO will be able to provide documentation to the developer community about the process used to create FDsys metadata for legislative, executive, and judicial content collections.
It can also be used to provide documentation about the FDsys sitemap implementation and supporting resources that are currently available on the FDsys Bulk Data Repository (e.g. User Guides).