Version control systems

Real projects can't do without them

• Allow multiple developers to contribute on the same project. Each developer can see the latest changes from the others, or choose to stick with older versions of some components.
• Allow to keep track of changes, and revert them if needed.
• Allow developers to have their own development branch (branching)
• Supposed to help developers resolving conflicts with different branches (merging)

Traditional version control systems

Rely on a central repository. The most popular open-source ones:

• CVS - Concurrent Versions System
  • Still quite popular in enterprise contexts. Almost no longer exists in the open-source community.
  • Should no longer be used for new projects
  • http://en.wikipedia.org/wiki/Concurrent_Versions_System
• Subversion
  • Created as a replacement of CVS, removing many of its limitations.
  • Commits on several files, proper renaming support, better performance, etc.
  • The user interface is very similar to CVS
  • http://en.wikipedia.org/wiki/Subversion_(software)

Distributed source control systems

No longer have a central repository

• More adapted to the way the Free Software community develops software and organizes
• Allows each developer to have a full local history of the project, to create local branches. Makes each developer's work easier.
• People get working copies from other people's working copies, and exchange changes between themselves. Branching and merging is made easier.

• Make it easier for new developers to join, making their own experiments without having to apply for repository access.

• Git

  • Initially designed and developed by Linus Torvalds for Linux kernel development
  • Extremely popular in the community, and used by more and more projects (kernel, U-Boot, Barebox, uClibc, GNOME, X.org, etc.)
  • Outstanding performance, in particular in big projects
  • http://en.wikipedia.org/wiki/Git_(software)
• Mercurial
  • Another system, created with the same goals as Git.
  • Used by some big projects too
  • http://en.wikipedia.org/wiki/Mercurial http://en.wikipedia.org/wiki/Version_control_systems#Distributed_revision_control