Jenkins

Jenkins is the world's most widely deployed open source automation server, providing the foundation for continuous integration and continuous delivery pipelines in thousands of organizations ranging from open source projects to Fortune 500 enterprises. Originally developed as Hudson at Sun Microsystems in 2004 and later forked as Jenkins in 2011, the project is now maintained by the Jenkins community under the governance of the Continuous Delivery Foundation.

Jenkins Server is a self-hosted Java application that orchestrates software build, test, and deployment pipelines through a web-based interface and REST API. Jenkins supports a distributed build architecture where a Jenkins master coordinates work across any number of build agents running on physical machines, virtual machines, or containers, enabling horizontal scaling to accommodate growing build workloads.

Jenkins Pipeline is the recommended approach for defining CI/CD workflows in Jenkins, enabling teams to write pipeline logic as code using a Groovy-based DSL stored in a Jenkinsfile in the source repository. Declarative Pipeline provides a structured, opinionated syntax that simplifies common CI/CD patterns, while Scripted Pipeline offers the full flexibility of Groovy for implementing complex, conditional pipeline logic.

The Jenkins plugin ecosystem, comprising more than 1,800 community-developed plugins, is one of the most extensive in the DevOps tool space. Plugins provide integration with virtually every version control system, build tool, testing framework, artifact repository, notification platform, and deployment target that organizations might use. This flexibility makes Jenkins adaptable to almost any technology stack and organizational workflow.

Jenkins X is a cloud-native reimplementation of Jenkins for Kubernetes environments, providing opinionated CI/CD workflows with automatic preview environments, GitOps promotion, and native Kubernetes integration. Jenkins Configuration as Code (JCasC) enables teams to define Jenkins server configuration in YAML files, enabling reproducible Jenkins deployments and eliminating manual configuration drift in enterprise Jenkins installations.