The INET Framework lives in the inet-framework/inet repository on GitHub.
master: Holds the current stable version of INET (as of Jan 2019, version 4.x).
topic/<name>: Temporary branches opened for the development of a particular feature. Topic branches may be deleted, rebased, or their history rewritten at any time.
attic/<name>: Abandoned topic branches. They may be dead, or just resting.
Note: Most people contribute by forking the repository on GitHub and submitting pull requests to us.