Counting derivatives

In the news, there's an article by Bruce Byfield discussing the influence of Debian and its (transitive) derivatives on the ecosystem of GNU/Linux distributions: Linux Leaders: Debian and Ubuntu Derivative Distros.

The article is a sort of review of what you can find in the vast ecosystem of distributions rooted at Debian: from embedded to supercomputer distro, from netbook to scientific computing distros. The articles cites the Debian derivatives front desk and is a study similar to what we might tackle with the derivatives census by Paul Wise. (By the way: did you check if your favorite Debian derivative is already in? No? Do it!)

With this article, Bruce has made me quite a favor in harvesting distrowatch to refresh the figures about the number of derivatives that I often use in speeches. The need of doing that has been polluting my LaTeX "% TODO" comments for a while now… Here they are:

• 324 active distributions
• 129 of them are (directly or transitively) based on Debian
• 75 of the latter class are (directly) based on Ubuntu, i.e. transitively based on Debian

Update: update figures that Bruce misinterpreted; live data are available, thanks to Loris (see comments) for noticing