TeamTrick is an open source web application to implement Scrum. It will help you with all the tedious tasks of managing teams with Scrum. Here are some key features:
It really fits Scrum
From backlog to burndown, every key point of Scrum has been implemented on TeamTrick. Nice graphs will be generated based on work hours as long as other important values like team velocity or focus factor.
It's a web application
Team members can access TeamTrick wherever they are just pointing their web browser to the right address. Install TeamTrick on a server and you're done.
It's open source
TeamTrick is released under the AGPL license. You can use it, modify it and redistribute it for free.
It's easy to install
Web applications tend to be hard to install. This is not. Download, unzip and run. The only external dependency is Ruby.
Built with Ruby on Rails
Ruby on Rails is one of the most powerful frameworks for web applications. It's multi platform and makes code really easy to understand and maintain.