I seem to have settled on Mercurial for now, as I’ve been using it for both school and personal projects over the past few weeks. However, all of these tools have facilities to make conversions between them possible, and even easy (NO WAY!), in some cases. In addition, they also all have support for reading from Subversion repositories. If I happen to change my mind next week I can convert my repositories to another format and use another VCS, which is pretty cool. I’ve broken down the main differences between these tools below, however don’t worry, I will post a more detailed review sometime next week.
Mercurial: Written in Python and works equally well on both Windows and Linux (apparently under other systems as well), and is used by projects such as NetBeans, Mozilla and OpenSolaris. The UI is well designed and the commands are easy to get used too, especially if you have used Subversion or CVS (if you are still using CVS for the LOVE OF GOD upgrade to Subversion!) before. The output is completely customizable, which makes it perfect for scripting, and it includes all the repository hooks bells and whistles. My personal favorite.
Bazaar: Smaller market share than Mercurial or Git, but I have very few complaints. It is used by Canonical Ltd. to manage the Ubuntu linux distribution, and works great under both Windows and Linux. It does seem a tad less responsive, but not by much, and the performance improves with every release. Bazaar also has direct support for the “centralized” version control model (a la Subversion/CVS/Perforce, etc), which saves you an extra command if you use that model for a project. (In Mercurial/Git/Darcs you need to do an extra “push/pull” to communicate with the “central” repository). The conversion tools are also excellent.
Git: Originally made of up several C programs stuck together with bash and Perl scripts, this tool adheres to the UNIX philosophy of using several small tools, with each one doing one task really well. Git has since evolved to be a great VCS, and is most notably used to manage the Linux kernel. The main shortcoming is its lack of Windows support. It will run with Cygwin, but that is not an option for the average user. If everyone involved in the project uses Linux, Git is definitely worth a look. There is also a great interface for communicating with Subversion repositories, git-svn.
Darcs: Written in Haskell, and uses a “patch algebra” for changesets to make merging easier. Performance is on par with the rest, although I’ve heard of a few cases where a merge can take hours where it should have taken seconds. However, Darcs is still in its early stages and has some interesting ideas. Like Git, it does not work well in Windows, but for some people that is not an issue. I wouldn’t trust it with a corporate project, but definitely worth a look.
While you’re waiting for the more in-depth reviews, check out these other comparisons:
http://www.dribin.org/dave/blog/archives/2007/12/28/dvcs/
