Socket.io - Realtime application framework (Node.JS server)

StatCounter - StatCounter is a simple but powerful real-time web analytics service that helps you track, analyse and understand your visitors so you can make good decisions to become more successful online.

Pusher - Pusher is a hosted API for quickly, easily and securely adding scalable realtime functionality via WebSockets to web and mobile apps.

AFSAnalytics - AFSAnalytics.

Primus - Primus, the creator god of the transformers & an abstraction layer for real-time to prevent...

Woopra - Track your customers' web and mobile activity, forms, emails, support tickets and more, all in one place with customer analytics. Analyze and take action.