Crabgrass is a free web application that has been specifically designed for communication within social change organizations. Crabgrass software provides activists with a suite of online tools that aim to enable organization, collaboration, and networking.

The current Crabgrass toolkit includes private wikis, task lists, file repository, and decision making tools.

http://crabgrass.riseuplabs.org/

https://we.riseup.net/crabgrass/about