msrp4j is a Java library for the MSRP protocol defined by RFC 4975. MSRP is a TCP protocol for transmitting messages containing arbitrary content between peers. MSRP can be thought of as a TCP/IP version of SMS/MMS text messaging.
msrp4j implements the actual MSRP protocol itself. The setup and/or negotiation of MSRP sessions must be handled by other means; this is typically done via SIP.
msrp4j also includes an executable command line test client.
Documentation is provided by API Javadocs.
There is also a Maven Site.