JSR331 “Java Constraint Programming API” is a JCP Specification Standard developed under the terms of the www.JCP.org. Now it also has its own website: www.jsr331.org. You can download the latest JSR-331 version, see different milestones, and read all release notes. While the software is in a stable state and is used in production environments by various companies, we keep adding new features based on the real-world user requests. You may try JSR-331 and use it for free and without limitations. Please send your suggestions for improvement to firstname.lastname@example.org.