I just released 0.50 of RPC::XML and no, you didn't miss any interim releases. I bumped the number up to reflect that the package has some very extensive new features, though almost all are behind-the-scenes changes that aren't obvious (indeed, they should be as inconspicuous as possible).
The main reason for this is that my day job is using this package in an application that sends Very Large messages containing base64-encoded audio. I don't know that I can say what it is at this stage, but it showed me that having the whole XML-RPC message in memory at once wasn't always a good thing. So this version addresses that on two fronts:
On another note, I've realized that I can't really make either of the Apache::RPC::Server or Apache::RPC::Status modules work under Apache2/mod_perl2 with the compatibility layer. I will have to (eventually) develop new classes entirely for use in MP2 environments. Sorry if this impacts anyone negatively.
For every complex problem there is a solution which is simple, neat and wrong. H.L. Mencken