Jenkins is an open source continuous integration tool written in Java, that has packages for Linux, Mac OS X, Windows, FreeBSD and OpenBSD. The project was forked from Hudson.
The Jenkins project started life as hudson in 2004, but the user and developer community decided to rename the project to Jenkins in early 2011 after oracle asserted trademark claims to the name Hudson (see hudson for questions related to the previous name).
Jenkins lets you automate many tasks, such as compilation, tests and deployments. Jobs can be scheduled using cron-like scheduling, or using triggers, such as whenever a source code repository is updated.
Jenkins is Java-based and recent versions require Java 8 (or later) on the master. The Jenkins master can manage multiple build nodes (slaves). Jobs can be run across multiple machines in order to perform jobs in parallel, distribute load, or build and test cross-platform software. Capacity can be easily added — Jenkins can automatically set up a new build slave on any SSH-accessible machine; it can even launch new machines to run jobs on, e.g. via cloud-computing or virtualisation plugins.
Jenkins supports a long list of plugins in a wide variety of categories to support different source control systems, run specialised build tools, send notifications, provide build reports and analytics, customise build workflows, etc. Many jenkins-plugins are hosted as open source under the Jenkins organisation on GitHub.
Jenkins is an open-source project with an enhanced enterprise product managed by CloudBees. The open source software is hosted on GitHub and distributed under the MIT license. There is an active development community with public documentation, getting started tutorials and a wiki. A new version is released approximately once a week, with more stable "long-term support" releases roughly every six months.
