The Stomp project is the Streaming Text Orientated Messaging Protocol site (or the Protocol Briefly Known as TTMP and Represented by the symbol :ttmp). Its a simple and easy to implement protocol for working with Message Orientated Middleware from any language.
- WS-Ramp - SOAP based asynch messaging profile
- WS-ReliableMessaging - SOAP based asynch messaging profile
- WS-Reliability SOAP based async messaging profile. I think this one has fallen out of favor with the WS-Glitterati
- XMPP - XML based messaging protocol originally created for IM, but not really bound to it.
- TOC- Text oriented messaging protocol created for interop with AOL Instant Messenger. I've seen people use it for arbitrary asynch messaging, so am listing it. Please don't serioulsy consider it.