I agree with this answer, but wanted to add a few points.
In short, Hudson (update: Jenkins) is likely the better choice now. First and foremost because creating and configuring jobs ("projects" in CC vocabulary) is just so much faster through Hudson's web UI, compared to editing CruiseControl's XML configuration file (which we used to keep in version control just to keep track of it better). The latter is not especially difficult - it simply is slower and more tedious.
CruiseControl has been great, but as noted in Dan Dyer's aptly-named blog post, Why are you still not using Hudson?, it suffers from being first. (Um, like Britain, if you will, later into the industrial revolution, when others started overtaking it with newer technologies.)
We used CruiseControl heavily and have gradually switched over to Hudson, finally using it exclusively. And even more heavily: in the process we've started using the CI server for many other things than before, because setting up and managing Hudson jobs is so handy. (We now have some 40+ jobs in Hudson: the usual build & test jobs for stable and development branches; jobs related to releasing (building installers etc); jobs that run some (experimental) metrics against the codebase; ones that run (slow) UI or integration tests against a specific database version; and so on.)
From this experience I'd argue that even if you have lots of builds, including complicated ones, Hudson is a pretty safe choice because, like CC, you can use it to do anything, basically. Just configure your job to run whatever Ant or Maven targets, Unix shell scripts, or Windows .bat scripts, in the order you wish.
As for the 3rd party stuff (mentioned here by Jeffrey Fredrick) - that is a good point, but my impression is that Hudson is quickly catching up, and that there's already a very large number of plugins available for it.
For me, the two things I can name that I miss about CruiseControl are:
- Its warning emails about broken builds were more informative than those of Hudson. In most cases the root cause was evident from CC's nicely formatted HTML mail itself, whereas with Hudson I usually need to follow the link to Hudson web UI, and click around a little to get the details.
- The CruiseControl dashboard is better suited, out of the box, as an "information radiator" (shown on a public monitor, or projected on a wall, so that you can always quickly see the status of all projects). With Hudson's front page, we needed some Greasemonkey tricks to get job rows all nicely green/red.
Minor disclaimer: I haven't been following the CC project closely for the last year or so. (But from a quick look, it has not changed in any dramatic way.)
Note (2011-02-03): Hudson has been renamed/forked as Jenkins (by Hudson creator Kohsuke Kawaguchi and others). It looks as if Oracle—which controls the Hudson name—will keep "Hudson" around too, but my personal recommendation is to go with Jenkins, no matter what Oracle says.
