Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Datadog - See metrics from all of your apps, tools & services in one place with Datadog's cloud monitoring as a service solution. Try it for free.
Event Hunt - Startups and Tech Events Curated By Locals
AppDynamics - Get real-time insight from your apps using Application Performance Management—how they’re being used, how they’re performing, where they need help.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Zabbix - Track, record, alert and visualize performance and availability of IT resources