... Constrained Application Protocol (CoAP), a specialized RESTful transfer protocol for use with constrained networks and nodes for machine-to-machine applications such as smart energy and building automation. These constrained nodes often have 8-bit microcontrollers with small amounts of ROM and RAM, while networks such as 6LoWPAN often have high packet error rates and a typical throughput of 10s of kbit/s. CoAP provides the REST Method/ Response interaction model between application end-points, supports built-in resource discovery, and includes key web concepts such as URIs and content-types. CoAP easily translates to HTTP for integration with the web while meeting specialized requirements such as multicast support, very low overhead and simplicity for constrained environments.
git clone git://coapy.git.sourceforge.net/gitroot/coapy/coapy
Very rough now, not really pleasant to use, interfaces will change, improvement suggestions welcomed, not suitable for use by small children.