Are there any differences between the original CruiseControl and the .NET port? I've compared the 2, but can't find any big differences except the language it has been developed in. I want to use either one of them for (automated) testing of web applications, using Selenium and Subversion, perhaps even Groovy but don't know which to choose.
[edit] After looking at CC and Hudson, I've chosen Hudson for it's simplicity, it already has plugins to run Groovy scripts and Selenium as well
I think for you it will come down to operating system, original can run on nix, and .net version runs on windows.
There are other automated build utilities that can do this as well, such as TeamCity in the windows space, and cruisecontrol.rb in the ruby world.
Also there is a PowerShell based build utility called pSake that can poll subversion and perform tasks.
Choose me, choose me! (I work on the original CruiseControl.)
I've never used CC.NET but from what I know I agree that they are pretty comparable. Probably the most important difference is cross-platform vs. Windows only.
Now I wonder how long until someone comes by and says their both crap and you should try Hudson? ;)
(And of course there are lots of other choices...)
CruiseControl.NET (cc.net henceforth) has build queues (http://confluence.public.thoughtworks.org/display/CCNET/Project+Configuration+Block), which allows you to serialize builds that depends on a certain build order. I'm in the process of emulating this behavior in the java version of cruisecontrol but the functionality doesn't map one to one. The reason however, that I'm at all moving from the .net to the java version is that the .net version core dumps with mono (cc.net nightly build and mono nightly build as of two months ago). The fault lies with monos thread handling but voids attempts to get cc.net up and running.
The documentation on this can be tricky to find, if you don't notice the version numbers that the configuration examples/documentation adhere to (confluence.public.thoughtworks.org has the updated configuration documentation whereas ccnet.sourceforge.net has not. I know that the ccnet is most likely a dead site, but if your're not carefully reading the datestamps on every page you're visiting, this may bite you).
Furthermore, the sourcecontrol blocks for cvs and svn in cc.net are more granular and featurerich than their counterpart in the java version, but this has not been a problem in my work. The java version is also easy to extend/modify re: plugin behavior, but you would really just like to see this kind of work going upstream instead of forking.
I'm fairly impressed with both the java version and the fork in .net (modulo mono runtime behavior), but you really do not want to try any of the other forks of cruisecontrol. I've had peripheral experience with hudson, and the features were just not compelling enough to veer me from cruisecontrol. Hudson has a (somewhat coloured) comparison map of Hudson and CruiseControl (java) at http://hudson.gotdns.com/wiki/display/HUDSON/Home
A viable alternative is the python implemented buildbot (http://buildbot.net/trac). It does not have fancy gui dashboards and the setup is somewhat more commandline-bound, but if you're doing distributed builds, it's very easy to set up and get running.