23.7 Version Control
Version control systems are packages that can record multiple
versions of a source file, usually storing the unchanged parts of the
file just once. Version control systems also record history information
such as the creation time of each version, who created it, and a
description of what was changed in that version.
The Emacs version control interface is called VC. Its commands work
with different version control systems—currently, it supports CVS,
GNU Arch, RCS, Meta-CVS, Subversion, and SCCS. Of these, the GNU
project distributes CVS, GNU Arch, and RCS; we recommend that you use
either CVS or GNU Arch for your projects, and RCS for individual
files. We also have free software to replace SCCS, known as CSSC; if
you are using SCCS and don't want to make the incompatible change to
RCS or CVS, you can switch to CSSC.
VC is enabled by default in Emacs. To disable it, set the
(see Customizing VC).