Eggplant is an open source web application that provides simple and flexible infrastructure for organizing food coops and other local community-driven projects.
We use Slack for ad-hoc communication: Click to recieve an invitation. The techical discussion takes place on IRC #eggplant (Freenode) and Slack#teamblue (both rooms automatically forward to each other). The design and organisational issues can also be raised on Slack#teamgreen.