Jira may be extremely sluggish and require a large amount of memory on the client side.
Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Asana - Asana project management is an effort to re-imagine how we work together, through modern productivity software. Fast and versatile, Asana helps individuals and groups get more done.
Bylde - Bylde is a SaaS platform you can use to Start, Manage and Grow your groups and communities.
Wrike - Wrike is a flexible, scalable, and easy-to-use collaborative work management software that helps high-performance teams organize and accomplish their work. Try it now.