Travis CI
A continuous integration service used to build and test software projects hosted at GitHub.
Operation
From: Wikipedia
When Travis CI has been activated for a given repository, GitHub will notify it whenever new commits are pushed to that repository or a pull request is submitted. It can also be configured to only run for specific branches, or branches whose names match a specific pattern. Travis CI will then check out the relevant branch and run the commands specified in .travis.yml, which usually build the software and run any automated tests. When that process has completed, Travis notifies the developer(s) in the way it has been configured to do so—for example, by sending an email containing the test results (showing success or failure), or by posting a message on an IRC channel. In the case of pull requests, the pull request will be annotated with the outcome and a link to the build log, using a GitHub integration.
Travis CI can be configured to run the tests on a range of different machines, with different software installed (such as older versions of a programming language implementation, to test for compatibility), and supports building software in numerous languages, including C, C++, C#, Clojure, D, Erlang, F#, Go, Groovy, Haskell, Java, JavaScript, Julia, Perl, PHP, Python, R, Ruby, Rust, Scala and Visual Basic. Several high-profile open source projects are using it to run builds and tests on every commit, such as Plone, Ruby on Rails, Ruby, and Node.js.