An upcoming web-based tool for sabermetrics. The tool will have a cooler name and URL at some point.
The idea is to have an open-source tool that can leverage free data sources from across the Web, and make them available via a "nice" interfaces, such as a JavaScript UI and a web-hosted API.
If you're a Github user, "Watch" this project to get updates.
You can also join the Google Group: https://groups.google.com/forum/#!forum/btr-baseball
Not much here yet: http://bryantrobbins.github.io/baseball/