HTTPR is an IBM introduced protocol for extending the HTTP protocol with network reliability features. HTTPR leverages HTTP version 1.1. As such, all of the facilities of HTTP/1.1 (SSL, keep-alive, communication through proxies and firewalls, and so on) are available.

HTTPR is rarely used. Its major limitation is that the reliability protocol is not decoupled from the transport protocol. Thus, if a payload were being sent across multiple nodes and multiple transport protocols were being used in the transit, it would be necessary to use multiple reliability protocols. Instead, the web services community is favoring transport neutral reliability protocols such as WS-Reliability

See: Transport Binding