In the process of reorganizing the tree, I have included the Apache IPP listener support on top of the PAPI. This was actually developed over a year ago, but has somehow never made it's way back into the source base. For those interested, the support is implemented as a set of libraries and Apache module. The libraries include support for on-the-wire protocol handling, and IPP operations dispatching and handling. The Apache module glues the dispatcher in under Apache and handles Apache configuration.
The mod_ipp code is designed so that it will work under either Apache 1.X or Apache 2.X. At compile time, you point it to the version of Apache that you want to run under and it builds the appropriate glue.