A CI server born at Sun
Hudson — Java-written continuous integration server — was created by Kohsuke Kawaguchi at Sun Microsystems from 2005 as a personal tool, progressively adopted by the Java community to become the most-used open source CI server in the world by the late 2000s. Plugin architecture, distributed build (master/agent), simple web interface, massive support for build languages and tools: Hudson is the standard choice in thousands of projects, from single developers to enterprise projects with thousands of jobs.
The Oracle dispute
In January 2010 Oracle acquires Sun Microsystems. By late 2010 a dispute emerges between Oracle and the Hudson community over:
- Trademark control of Hudson — Oracle registers and claims it
- Project governance — Oracle proposes moving Hudson to an Oracle-controlled infrastructure; the community prefers more open governance
- Contribution policy — tensions on who can make releases
The fork
In January 2011 the Hudson community votes by an overwhelming majority (over 90%) to fork the project under a new name. The chosen new name is Jenkins. Kohsuke Kawaguchi — original author, who had in the meantime left Oracle — moves with Jenkins along with the majority of the community and committers.
The first Jenkins release (1.396, renamed from Hudson 1.395) is out on 11 February 2011. MIT licence.
Hudson stays with Oracle, which transfers it to the Eclipse Foundation. Though development continues, Hudson rapidly loses relevance: in 2016 the Eclipse Foundation will formally archive the project.
Jenkins, by contrast, grows:
- Plugins — over 1000 already in the first year, one of the richest open source ecosystems
- Industrial adoption — Netflix, Twitter, LinkedIn, Yahoo, Amazon (with enterprise-scale configurations)
- Jenkins Pipeline (2016) — Groovy DSL for CD as code
- Blue Ocean UI (2017) — GUI rewrite
- Jenkins X (2018) — Kubernetes-native evolution
Post-fork governance
Jenkins adopts explicit governance: Jenkins Project Board, public decision processes, CLA (Contributor License Agreement), infrastructure hosted by Software in the Public Interest. In 2019 the project will formally enter the Continuous Delivery Foundation (Linux Foundation).
The Hudson/Jenkins fork becomes a case study in open source literature for:
- Control dynamics between corporate sponsor and community
- Importance of trademark and independent governance
- Resolution mechanisms when trust breaks down
- Empirical demonstration that an active community can prevail over a vendor holding only the name
Jenkins’ technical value
Regardless of history, Jenkins concretely solves:
- Automatic build on every commit
- Continuous testing with integrated reports (JUnit, TestNG, coverage)
- Distributed build — master coordinates, agents run in parallel
- Integration with over 1000 tools — Git, Maven, Gradle, Ant, Docker, Kubernetes, cloud providers, Slack/email notifications, deployment tools
- Pipelines as code —
Jenkinsfileversioned in Git alongside the code
In the Italian context
As of 2011 Jenkins/Hudson is already widespread in Italian Java development teams. The fork does not cause notable fragmentation: most installations migrate to Jenkins within a few months, following the community path and plugins (which rapidly move to the new platform).
The fork’s legacy is a lesson: open source sustainability depends on controlling the name and governance, not only the code’s licence. This principle will influence the choices of many subsequent projects (OpenStack, Apache CloudStack after original CloudStack, MariaDB after MySQL/Oracle).
References: Jenkins 1.396 (11 February 2011), fork from Hudson 1.395. Kohsuke Kawaguchi. MIT licence. Oracle vs. community trademark dispute, January 2011. Eclipse Foundation (post-fork Hudson). Continuous Delivery Foundation (Linux Foundation) from 2019.