4S uses Git and Bitbucket for source control and it is hosted on https://bitbucket.org/4s.
The source code for the public projects in 4S are generally accessible. You need to sign up in order to push code to the repository. Click Log in in the upper right corner to log in or sign up. You can use an existing Atlassian OnDemand account, other Oauth accounts, or create a new account.
In general, please see our detailed guides and requirements regarding contributing changes to 4S code, tests and documentation
You follow a normal Git process when working with the 4S code bases. You can work with the normal clone & push scheme, when you have sufficient access rights to the 4S repositories, see Bitbucket help. You have to use a fork & pull request scheme in the cases where you do not have sufficient access rights, see Bitbucket help.
4S has defined a branching strategy for the open source projects, which is described in detail under branching strategy.