Replying to Thomas P. :

No, HTTaP is not directly compatible with HTCPCP  or its extensions because they work at a lower level. HTTaP works at a higher level, above the server level, using the HTTP protocol to transmit the data as payload instead of in the headers and meta-information.

Thomas is free to implement similar functionalities using the HTTaP features and protocol for the next April, 1st ;-)