The Apache website has an interesting build and project management tool/framework called ‘Mavern’ which is fast becoming popular for a number of Open Source projects.
OnJava.com have an introductory article about the framework on their site.
Mavern automates a lot of the project build tasks that are common to most large projects, including: code compilation, creating JavaDoc, running JUnit TestCases, performing code analysis and producing reports (code standard violations etc), and producing reports of version control repository activity and status.