FreeBSD maintains a presence on GitHub with all project SVN repositories mirrored:
Currently, pull requests are not officially accepted, but some project members do sometimes process/close them manually. The recommended method for submitting changes to FreeBSD is via Bugzilla
A number of well-known FreeBSD software projects maintain their primary repositories there are well:
Issue reports and pull requests are open on these projects.
Requests to be added to the FreeBSD GitHub Organisation can be made via Bugzilla (Product: Services, Component: Git Integration). Please include details of any teams you are a member of or hats you wear so that this can be reflected in GitHub.
Currently, only those with @FreeBSD.org accounts are approved in almost all cases. External users may apply to be a part of the organisation if a compelling case can be made. Examples may be external contributors that require write (commit) access to a non-FreeBSD (src, ports, doc) repository that is hosted within the organisation account.