Blazar is a continuous integration tool designed to integrate with GitHub (and/or GitHub Enterprise) and Singularity. It uses GitHub organization webhooks so that new repositories are automatically discovered, and the builds happen as one-off tasks in Singularity so you can reuse your existing cluster rather than running dedicated build servers.
The unit of build in Blazar is a module, which is an arbitrary subset of a repository. This allows Blazar to only build the parts of a repository that have changed when a commit is pushed, rather than building the entire repository every time. It uses a pattern similar to Heroku's buildpacks to discover the buildable units within a repository and to define how to do the build.
To run Blazar locally, run
mvn clean pre-integration-test -DskipTests -Dblazar.port=7199 to launch Blazar and its dependencies (Singularity, Mesos, and MySQL) in Docker containers. Then go to http://DOCKER_IP:7199/blazar/ in your browser. When you're done, run mvn docker:stop to shut down the containers.