Here’s a link to a large matrix of CI tools:

http://confluence.public.thoughtworks.org/display/CC/CI+Feature+Matrix

Here’s my own list with basic impressions

• CruiseControl – a bit old
• Continuum – Apache
• Luntbuild – Dead simple, but not that intuitive or extendible. Usually end up cloning and tweak
• Hudson – Looks very interst
• Anthill – not open source?
• Bamboo – Atlassian
• Teamcity – Intellij
• CruiseControl.NET – .NET based, I hear it’s much more featureful than regular cruisecontrol.

Others to look at:

• Tinderbox – Mozilla
• Pulse
• BuildBot – Python
• Cerberus – Ruby based