I think it's partly an artifact: due to a naming conflict, the git package in Debian used to be named "git-core" and was renamed "git" around then.

Looks like that might be the case, if you combine the graphs of git-core and git, you get a roughly-exponential growth shape:

http://qa.debian.org/popcon-graph.php?packages=git+git-core&...

I keep tacking RCS onto the ends of these, too :) It keeps surprising me - Mercurial passed RCS ~ last June, and Bazaar passed it in roughly June of this year. It gets a lot of usage still.

I use it pretty often for casual alteration of configuration files.

Why do you prefer it to git or hg for this use case?

This whole article has been rendered silly based on this observation. Yes git's popularity has increased and passed subversion but it was a long time coming and not an explosion at all.

I'd imagine that many projects moving to Gitorious/GitHub as opposed to, say, SourceForge has a role here. According to Wikipedia GitHub gained 1 million new repositories between July 2010 and April 2011. Sourceforge currently has some 300k projects. Not completely an apples to apples comparison but I'd think it gets the general idea. Technically, Git lends itself to "social coding" much better than SVN IMO.

Also, last time I checked, SourceForge has an application process involved in establishing a repository, while Github is just "register and create as many as you like"

With many interesting open source projects migrating to or being started on GitHub, almost everyone depending on such tools will install Git for client usage.

It doesn't necessarily mean Git is that rapidly surpassing SVN in actual use as repository, that is likely to happen way slower than the growth of the install base.

Every use of git is a repository, it's the nature of the distributed beast. In fact I would argue the opposite, git probably has a few orders of magnitude the number of repositories than svn does; even the servers I use for production deployments have 10s of git repositories on them.

I wonder if some popular Debian package happened to specify git as a package dependency, thus installing git for people who did not actually use it?

In a few cases; gettext recommends autopoint, which depends on git, so it will be installed automatically if someone installs gettext.

A few packages depend on gettext that I wouldn't have expected, like blender. This might be a mistake, but anyone who installs Blender will also install git, without ever using it.

Positive network externalities: the more people who use it, the more valuable it is, which creates more incentives to use it yourself.

GitHub?

not likely. see http://siteanalytics.compete.com/github.com/ and http://www.google.com/trends?q=git%2C+mercurial%2C+svn%2C+gi...