Real-time data is a big deal and here are a few popular services I've used to build web apps.

I went ahead and organized this a bit differently. I tried to organize the various services available for distributing data and their relationship with you.

You own, manage and distribute your own data

Do It Yourself

• FeathersJS is a thin wrapper on top of ExpressJS.
• Faye
• SocketJS attempts to offer WebSocket-first functionality with websocket-like fallback.
• Gun
• Remote Storage
• Socket Hub
• Unhosted

You own your data but let someone else to manage and distribute it

Infrastructure as a Service

• Firebase
• CartoDB
• Dropbox
• Google Plus
• PubNub
• Socket.io

Let someone else own, manage and distribute your data

Web 2.0's monopoly platforms

• Facebook
• Twitter

Let someone else own your data but you manage and distribute it

NEVER SEEN THIS BEFORE

Resources

• Quora's Response to Firebase alternatives