Maven is Java project management, project comprehension and build system tool.
Fedora 15 comes with Maven version 3.0. It offers better stability and performance compared to previous versions, but the biggest changes shouldn't be noticed by users. Most work has been happening under the hood to simplify writing Maven plugins and further improve performance by building projects in parallel. It includes a new Maven API for component configuration, many improvements and bug fixes. Users of Maven are encouraged to read the Maven 3 Upstream Release Notes
Fedora 15 still provides maven2 package to support backward compatibility where needed.