Artifactory: Maven Repository Manager
Artifactory [1] is a Maven 2 Enterprise Repository Manager and Proxy. Enables local deployment of accessible, browsable, secured, and backed up maven2 repositories.
Artifactory (Apache License V2.0) is written in Java and its WebGUI is based on Apaches Wicket. Artifactory 2.0 has just been released. See the release annoucement and try out the demo.
It can be downloaded on SourceForge.net.