I wasn't really thinking about communication tools yet. I guess I'm old school and would probably prefer some google group but this isn't definitely a decision I have some strong opinion about.
My idea is to check with the community and work with whatever it prefers.
I think the first step would be to check with the other communities (Roda, Sinatra, Cuba, what else?) and see if they would be interested and which tool they would prefer. I'll try to send an e-mail on their mailing lists and will ask them about this.
We could also have framework/library agnostic documentation when it makes more sense, including describing techniques to move an existing project to a new stack and so on. We could simply write those in the Wiki if we can agree on the subject or we could simply link to other external articles on the subject when the opinions would vary a lot. It's somewhat what would be a an "awesome non-Rails ruby web development"
If you prefer, just let me know your e-mail and I can send a preview so that you can review it before I send the idea to Roda, Sinatra and Cuba mailing lists. Does that make sense?