Comparisons Are Odorous...

...but useful. Here's a nice analysis of the rather crowded open source systems management sector, with a graph of downloads by month. As the post notes:

The volume of downloads is indicative, like search trends, of the relative mind share for each project. Download volume isn’t a perfect measure, but it is one of the best available. I doubt even the projects themselves have an absolutely accurate idea of how many installations they have.

(Via 451 CAOS Theory.)