In revision control systems like Subversion, Git or CVS, a commit adds the latest changes to [part of] the source code to the repository, making these changes part of the head revision of the repository. Thus, when other users do an UPDATE or a checkout from the repository, they will receive the latest committed version, unless they specify they wish to retrieve a previous version of the source code in the repository. Version control systems allow rolling back to previous versions easily. In this context, a commit within a version control system is protected as it is easily rolled back, even after the commit has been done.
Years, where available, indicate the date of first stable release. Systems with names in italics are no longer maintained or have planned end-of-life dates.
