Debugging the Web of Things
This site, run by the TZI, was built to support the ETSI CoAP plugtest.
After this plugtest passed with some 20 implementations, over 3000 tests and more than 94 % successful interoperability, we decided to keep the site up. You can go on and use the site to test your CoAP implementations. You can use the http frontend to test your CoAP servers, or use the CoAP server at coap://coap.me to test your CoAP clients (use the frontend against the CoAP server to see what resources it offers).
Please see the CoRE Roadmap for what CoAP and CoRE is all about. The CoRE Wiki has some more pointers. For a current view of the ecosystem around CoAP, see the coap.space site.
Please report any problems and suggestions to Carsten Bormann.