High Quality Content by WIKIPEDIA articles! Mercurial is a cross-platform, distributed revision control tool for software developers. It is mainly implemented using the Python programming language, but includes a binary diff implementation written in C. It is supported on Windows and Unix-like systems, such as FreeBSD, Mac OS X and Linux. Mercurial is primarily a command line program but graphical user interface extensions are available. All of Mercurial`s operations are invoked as arguments to its driver program hg, a reference to the chemical symbol of the element mercury.