Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Zoom - Equip your team with tools designed to collaborate, connect, and engage with teammates and customers, no matter where you’re located, all in one platform.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
WebEx - Cisco WebEx Web Conferencing, Online Meetings, Desktop Sharing, Video Conferencing
Bylde - Bylde is a SaaS platform you can use to Start, Manage and Grow your groups and communities.
GoToMeeting - GoToMeeting is a web conferencing service offering a range of services which are available on Mac, PC, iOS and Android devices.