We are currently using Forums as an approximation of Scrum - one of the versions of "Agile" development. Drupal Forums were handy (i.e. already in place). Modest efforts have been made to flesh out some examples. After two weeks, the results are not encouraging.

As the most ardent advocate, my own level of compliance is meager. Team compliance even less.

Looking for the magic "pill", I found the NetBeans people were using "Teamwork" - http://www.twproject.com/home.page

Teamwork is written in Java and the web component runs under a web server with Java support. Their recommendation is "Tomcat". Early experience with Tomcat (Jasper Server) suggested that "Tomcat" was not a "good neighbor" for Apache/PHP. Although the source is available (GPL), the installer leads to a per user fee. Tomcat is a task/project in itself.

I do not know of a PHP alternative.