Domnic Mendes, who had a positive experience with this tool, thought CruiseControl would be a good addition to Cool Tools.

CruiseControl is a framework for a continuous build
process. It includes, but is not limited to, plugins
for email notification, Ant, and various source
control tools. A web interface is provided to view the
details of the current and previous builds.

CruiseControl is distributed under a BSD-style license
and is free for use. CruiseControl adheres to an open
source model and therefore makes the source code
freely available.

CruiseControl is composed of 2 main modules:

• the build loop: core of the system, it triggers
  build cycles then notifies various listeners (users)
  using various publishing techniques. The trigger can
  be internal (scheduled or upon changes in a SCM) or
  external. It is configured in a xml file which maps
  the build cycles to certain tasks, thanks to a system
  of plugins. Depending on configuration, it may produce
  build artifacts.

• the reporting allows the users to browse the
  results of the builds and access the artifacts.

This modularity allows users to install CruiseControl
where it will best fit their needs and environment.

Using remoting technologies (HTTP, RMI), it is
possible to control and monitor the CruiseControl
build loop. Those are turned off by default for
obvious security reasons.

CruiseControl can be installed from source, or using
the all in one binary installation.