This data is interesting for certain purposes, but it is a bit misleading when it comes to trying to compare license usage.
It doesn't take into account that the GPL is intended to consolidate efforts while the other licenses are not. The nature of the GPL is that code tends to be contributed to the main project, and even forks usually either get re-absorbed into the main project or become the new main project. There are generally one or perhaps two forks of any project that continue to be maintained while the others wither while giving back any code that was worthwhile to the maintained fork(s).
Related to this is that the data is presented as percentages of the total number of projects rather than the number of users of projects. Because of the nature of the GPL, number of users for their projects tends to go up to much greater levels. Code that is maintained under one of the other licenses only tends to get really big in a project that is either entirely sponsored by a large company or one that ends up treated like a more copyleft project where most code gets consolidated into one big open branch and there are no really significant forks.
Also, the intended use of the project makes a big difference. Libraries for interoperability promoting a standard are much more likely to be released under a permissive license to promote their use in many places, while whole applications have a better chance of being released under a pure copyleft license so they won't be appropriated into a commercial venture.
I just thought it would be of note, since xmms was brought up, that Audacious was forked from it a long time ago because development for it was effectively dead.
This data is interesting for certain purposes, but it is a bit misleading when it comes to trying to compare license usage.
It doesn't take into account that the GPL is intended to consolidate efforts while the other licenses are not. The nature of the GPL is that code tends to be contributed to the main project, and even forks usually either get re-absorbed into the main project or become the new main project. There are generally one or perhaps two forks of any project that continue to be maintained while the others wither while giving back any code that was worthwhile to the maintained fork(s).
Related to this is that the data is presented as percentages of the total number of projects rather than the number of users of projects. Because of the nature of the GPL, number of users for their projects tends to go up to much greater levels. Code that is maintained under one of the other licenses only tends to get really big in a project that is either entirely sponsored by a large company or one that ends up treated like a more copyleft project where most code gets consolidated into one big open branch and there are no really significant forks.
Also, the intended use of the project makes a big difference. Libraries for interoperability promoting a standard are much more likely to be released under a permissive license to promote their use in many places, while whole applications have a better chance of being released under a pure copyleft license so they won't be appropriated into a commercial venture.