After many months of polishing, the Hibernate team is happy to release Hibernate Validator 4. This is a major milestone for Hibernate Validator with tons of new features and a spec compliance.
In short, new features include constraint composition, groups, type-safe constraint declaration, more powerful custom constraints, native integration with JPA 2 and JSF 2, fluent type-safe bootstrap API, metadata API, XML deployment descriptor, a much improved test suite and last but not least the compliance with JSR-303 Bean Validation.
Check out this blog entry
for more details and info on how to download Hibernate Validator.