One important difference between Hudson Open Source and Hudson Professional is how they support Maven 3.
Sonatype has developed state-of-the-art support for Maven 3 focusing on creating seamless integration between the internals of Hudson CI and Maven. Year of work on Maven 3 internals to support more efficient embedding along with our multi-year investment in bringing both JSR-330 support and GWT UI integration to Hudson CI has produced a CI system that support Maven 3 like no other on the market.
If you’ve used Hudson and Maven together in the past, you might be familiar with the Maven 2 project type that provides users with the ability to define a Maven build that is aware of a project’s POM. While we understood the motivation for a Maven-specific project type, we took our Maven support in an entirely difference direction. We created a Maven build that can be used a part of a larger freestyle build, and the reason we did this was to get away for the idea that a Maven build can only include one step, one call to a series of goals.
Sonatype found this to be more of a limitation than an advantage.