VersionEye is tracking Open Source Software Libraries in the Internet. VersionEye is not interested in SourceCode. VersionEye is only interested in ready releases. In Artefacts that are “done” and you can reuse in your projects. The Graph down shows the amount of projects per language.
These numbers are collected from more than 50 different repository servers in the Internet, i.e. repository servers such as RubyGems.org, pypi.python.org, packagist.org and more than 40 Maven repository servers. SCM tools such as GitHub or BitBucket are not included.
This numbers contain only Software Library projects. Desktop Tools written Java and hosted on SourceForge are not included.
The following graph shows the growth of the repositories over time.
VersionEye started to crawle Repositories in April. That’s why we can not go further back in time. But the last couple months are already enough to show the growth speed of the repositories. If RubyGems is continuing to grow this fast, than soon it will be number 1.
You can check out the daily updated graphs at VersionEye: https://www.versioneye.com/statistics
Robert Reiz 
Somebody on Twitter asked why we are not crawling GitHub and BitBucket.
I really like GitHub and BitBucket, they are great SCM tools. But they are no Repository Managers. My Java and Ruby package managers (Maven & Bundler) are fetching the libs from search.maven.org and from RubyGems.org.
There is a lot of cool stuff on GitHub and BitBucket, but also a lot of forked “bullshit” many “test”, “play” and tutorial projects. This is not the focus from VersionEye.
And not every project is on GitHub & BitBucket. Many Java projects on search.maven.org are hosted on sourceforge, google code or some public company servers.
By the way. VersionEye is not tracking any SNAPSHOT Repositories. Only “production” Repositories.