Mercurial is a free, distributed source control management tool. It efficiently handles projects of any size and offers an easy and intuitive interface. Mercurial efficiently handles projects of any size and kind. Every clone contains the whole project history, so most actions are local, fast and convenient. Mercurial supports a multitude of workflows and you can easily enhance its functionality with extensions. Mercurial strives to deliver on each of its promises. Most tasks simply work on the first try and without requiring arcane knowledge. The functionality of Mercurial can be increased with extensions, either by activating the official ones which are shipped with Mercurial or downloading some from the wiki or by writing your own. Extensions are written in Python and can change the workings of the basic commands, add new commands and access all the core functions of Mercurial.