Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Envoy - Visitor registration that's changing how guests are greeted in companies around the world.
Event Hunt - Startups and Tech Events Curated By Locals
Proxyclick - Connect with Confidence
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
TractionGuest - Safe, secure workplace for all.