Jenkins

Jenkins is an open-source automation server built in Java, extended through more than 2,000 plugins that cover source control integrations, build tools, testing frameworks, deployment targets, and notification systems. Rather than shipping a fixed set of integrations, Jenkins is designed to be assembled into a CI/CD pipeline tailored to a team's specific toolchain.

It's one of the longest-running and most widely deployed CI/CD tools in active use, with regular releases, a long-term-support release line, and an active plugin ecosystem maintained by both the core team and the community.

Jenkins is a fit for teams that need a highly extensible, self-hosted CI/CD server that can integrate with a broad and sometimes unusual mix of tools, rather than a more opinionated, lighter-weight pipeline runner.