Apache Continuum has been retired.

https://continuum.apache.org/

Continuous integration server with features such as automated builds, release management, role-based security, and integration with popular build tools and source control management systems

Snippet from Wikipedia: Apache Continuum

Apache Continuum, is a discontinued continuous integration server. It was a partner to Apache Maven, which run builds on a configurable schedule. Much like CruiseControl, Continuum emailed developers when the build was broken, requesting that the culprit fix the problem.

The project was retired in May 2016