"big-zoo" is a collection of darcs repos, the darcs developers do benchmarks using this collection from release to release.
Recently our old Frugalware repo has been added, which is good, for multiple reasons.
First, now I can say that the reference for a good darcs exporter is the big-zoo, our old repo contains weird patches which were not yet part of "big-zoo" so far. Not that I'm evil, but I want to show that currently darcs-fast-export is the only exporter that can correctly convert all the repos in "big-zoo".
Second, it is a huge repo, so developers can how see the corner cases where darcs is really slow for a huge repo - though the GHC one was already included which is almost as big as our one and the most annoying cases are already optimized recently. (No, of course I can't compare it to git, I compare it to darcs-1.x.)