What are the realtime communication protocols available for the web?

Question

I recently came across WebSockets and my mind was blown about the possibilities they bring. I searched for a full list of such realtime (and near-realtime) communication protocols and technologies - such as XMPP, WebRTC but I couldn't find any near complete list. So please help me assemble the list here.

UPDATE: I'm looking for realtime protocols available for the web.

Answer 1

WebSocket

WebSocket is a web technology providing full-duplex communications channels over a single TCP connection. The WebSocket API is being standardized by the W3C, and the WebSocket protocol has been standardized by the IETF as RFC 6455.

XMPP (Jabber)

Extensible Messaging and Presence Protocol (XMPP) is a communications protocol for message-oriented middleware based on XML (Extensible Markup Language).

WebRTC

WebRTC (Web Real-Time Communication) is an API definition being drafted by the World Wide Web Consortium (W3C) to enable browser to browser applications for voice calling, video chat and P2P file sharing without plugins.

The Bayeux Protocol

Bayeux is a protocol for transporting asynchronous messages (primarily over HTTP), with low latency between a web server and a web client.

Server-Sent Events

Server-Sent Events (SSE) are a way for server to initiate data transfer to clients after the client connects. It is used for streaming continuous or low latency messages to the client. The browser API is called EventSource.

Wave Federation Protocol

The Wave Federation Protocol (formerly Google Wave Federation Protocol) is an open protocol, extension of the Extensible Messaging and Presence Protocol (XMPP) that is used in Apache Wave. It is designed for near real-time communication between the computer supported cooperative work wave servers.

IRC

Internet Relay Chat (IRC) is a protocol for real-time Internet text messaging (chat) or synchronous conferencing. It is mainly designed for group communication in discussion forums, called channels, but also allows one-to-one communication via private message as well as chat and data transfer, including file sharing.

Real-Time Publish-Subscribe (RTPS) Protocol

The Real-Time Publish-Subscribe (RTPS) protocol is designed for use with Internet Protocol (IP) one-to-many Multicast and connectionless best-effort transports such as IP User Datagram Protocol (UDP). It enables, among other things, best-effort and reliable publish-subscribe communications for real-time applications using standard IP networks.

Socket.IO

Socket.IO is a popular library for real-time communication from a browser. Socket.IO primarily uses the WebSocket protocol, but if needed can fallback on multiple other methods, such as Adobe Flash sockets, JSONP polling, and AJAX long polling, while continuing to provide the same interface. Although it can be used as simply a wrapper for WebSocket, it provides many more features, including broadcasting to multiple sockets, storing data associated with each client, and asynchronous I/O.