I've launched several communities that have made a difference in the world. I remain impressed with what can be done by folks with noble goals, public interest and a willingness to share the work without pecuniary interest.
Twelfth Principle says, Build projects around motivated individuals. Give them the environment and support they need, and trust them to get the job done.
Agile Uprising says it is a purpose-built network that focuses on the advancement of the agile mindset and global professional networking between and among practicing agilists.
Agile Alliance is not-for-profit 501(c)(6) trade association devoted to the improvement of business conditions in the software industry in accordance with the Agile Manifesto.
I can't speak for these organizations but they have caught my attention, not always positive.
Portland XP User's Group is one of many around the world. Here we see the report after the first meeting.