Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Fig - Fast, isolated development environments using Docker.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Teleconsole - Teleconsole is a free service to share your terminal session with people you trust.
Bigtent - BigTent is a web-based organization and communication portal for groups.
Shell Notebook - MacOS Terminal, reimagined