Mercurial (software)

Infobox Software
name = Mercurial



caption =
developer = Matt Mackall
latest_release_version = 1.0.2
latest_release_date = release_date|2008|08|13
latest_preview_version =
latest_preview_date =
operating_system = Unix-like, Windows, Mac OS X
programming_language = Python and C
platform =
genre = Revision control
license = GPL v2
website = http://selenic.com/mercurial/

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. Mercurial was initially written to run on Linux. It has been ported to Windows, Mac OS X, and most other Unix-like systems. Mercurial is primarily a command line program. All of Mercurial's operations are invoked as keyword options to its driver program hg, a reference to the chemical symbol of the element mercury.

Mercurial's major design goals include high performance and scalability, serverless, fully distributed collaborative development, robust handling of both plain text and binary files, and advanced branching and merging capabilities, while remaining conceptually simple. It includes an integrated web interface.

The creator and lead developer of Mercurial is Matt Mackall. The source code is available under the terms of the GNU General Public License version 2, qualifying Mercurial as free software.

Technical information

Like Git and Monotone, Mercurial uses SHA-1 hashes to identify revisions.

For repository access via a network, Mercurial uses an efficient, HTTP-based protocol that seeks to reduce round-trip requests, new connections and data transferred. Mercurial can also work over ssh where the protocol is very similar to the HTTP-based protocol.

Documentation

A comprehensive reference manual, [http://hgbook.red-bean.com/ Distributed revision control with Mercurial] [cite book
author = Bryan O'Sullivan
date = 2007-01-01
title = Distributed revision control with Mercurial
url = http://hgbook.red-bean.com/] , has been written by Bryan O'Sullivan. The manual is freely available under the terms of the Open Publication License.

History

Mackall first announced Mercurial on April 19, 2005. [cite mailing list
author = Matt Mackall
date = 2005-04-20
title = Mercurial v0.1 - a minimal scalable distributed SCM
url = http://www.ussg.iu.edu/hypermail/linux/kernel/0504.2/0670.html
mailinglist = Linux-Kernel] The immediate stimulus for this was the announcement earlier that month by Bitmover that they were withdrawing the free version of BitKeeper.

BitKeeper had been used for the version control requirements of the Linux kernel project. Mackall decided to write a distributed version control system as a replacement for use with the Linux kernel. This project started at approximately the same time as another project called Git, started by Linus Torvalds with similar aims.

The Linux kernel project decided to use Git rather than Mercurial, but Mercurial is now used by many other projects, see below.

Related software

* GUI interfaces for Mercurial include "Hgk" (Tcl/Tk). This is implemented as a Mercurial extension, and is part of the official version. This viewer displays the directed acyclic graph of the changesets of a Mercurial repository. This viewer can be invoked via the command 'hg view', if the extension is enabled. hgk was originally based on a similar tool for git called gitk. There is also a Gtk client named [http://www.logilab.org/project/name/hgview hgview] written in pure python.

* Related tools for merging include "(h)gct" (Qt) and Meld.
* The convert extension allows import from CVS, Darcs, git, GNU Arch, Monotone and Subversion repositories.
* Netbeans IDE supports Mercurial from Version 6.
* [http://tortoisehg.sourceforge.net/ Tortoise Hg] provides a Windows user-friendly, right-click menu interface.
* [http://sharesource.org/project/visualhg/ VisualHG] is an Mercurial source control provider plugin for MS Visual Studio 2008.

Projects using Mercurial

Some projects using the Mercurial distributed RCS: [ [http://selenic.com/mercurial/wiki/index.cgi/ProjectsUsingMercurial Some projects that use Mercurial] ]
* Aldrin
* Audacious
* Dovecot IMAP server [cite mailing list
author = Timo Sirainen
date = 2007-05-19
title = CVS to Mercurial switch
url = http://www.dovecot.org/list/dovecot-news/2007-May/000044.html
mailinglist = Dovecot-news]
* Growl
* MoinMoin wiki software
* Mozilla [cite web
author = J. Paul Reed
date = 2007-04-12
title = Version Control System Shootout Redux Redux
url = http://weblogs.mozillazine.org/preed/2007/04/version_control_system_shootou_1.html]
* Netbeans [cite web
url = http://www.netbeans.org/servlets/ReadMsg?list=nbdev&msgNo=40342
title = Switch to hg.netbeans.org completed
month = January
year = 2008]
* OpenJDK [cite interview
subject = James Gosling
interviewer = Robert Eckstein
url = http://java.sun.com/developer/technicalArticles/Interviews/gosling_os1_qa.html
title = James Gosling on Open Sourcing Sun's Java Platform Implementations, Part 1
month = October
year = 2006]
* SAGE
* Sun's OpenSolaris [cite web
title = OpenSolaris SCM Project History
url = http://opensolaris.org/os/community/tools/scm/history/
date = 2006-10-05]
* the developers of Xen, a Hypervisor [cite mailing list
author = Ian Pratt
date = 2005-07-01
title = mercurial now live
url = http://lists.xensource.com/archives/html/xen-devel/2005-07/msg00003.html
mailinglist = Xen-devel]
* Oracle's Opensource Software like Btrfs [cite web
title = Oracle Opensource Software Repositories
url = http://oss.oracle.com/mercurial
date = 2008-08-25]

See also

* Distributed revision control
*List of revision control software
*Comparison of revision control software

References

External links

* [http://selenic.com/mercurial/wiki/ Official Mercurial Project Wiki]
* [http://lwn.net/Articles/151624/ Mercurial: an alternative to git] from LWN.net
* [http://genunix.org/wiki/index.php/Mercurial_for_TeamWare_users Mercurial for TeamWare users]
* [http://video.google.com/videoplay?docid=-7724296011317502612 Google TechTalk on Mercurial]
* [http://javaworld.com/javaworld/jw-09-2007/jw-09-versioncontrol.html?page=1 Subversion or CVS, Bazaar or Mercurial? Four open source version control systems compared]