Buildbot is a software development continuous integration tool which automates the compile/test cycle required to validate changes to the project code base.

CircleCI is a continuous integration and delivery platform.

Concourse is a pipeline-based CI system written in Go.

TeamCity is a Java-based build management and continuous integration server from JetBrains.

Buildkite is a CI and build automation tool that combines the power of your own build infrastructure with the convenience of a managed, centralized web UI.

Codeship is a fast and secure hosted Continuous Integration service that scales with your needs. It supports GitHub, Bitbucket, and Gitlab projects.

Jenkins is a self-contained Java-based program, ready to run out-of-the-box, with packages for Windows, Mac OS X and other Unix-like operating systems.

Travis CI is a hosted continuous integration service used to build and test software projects hosted on GitHub.