PWM let you organize your project in a Web 2.0 way.
Project Web Manager is a free open source project for organizing your projects. You can create units/projects/task and monitor them through a Web 2.0 interface.
MightyCal is a web-based calendaring system that aims to be the "MS Access {tm}" of the calendaring world. Built on Zope and Apache Cocoon, MightyCal provides the ability to develop custom calendars, with output in HTML, PDF, RTF & many other formats