I'm sorry to say it, but I think these guys are on the wrong track. To get the environment they're trying to build in mod_perl, all you have to do is set MaxRequestsPerChild to 1. Then the processes exit after one request and you get a fresh, pre-forked process with a pristine Perl interpreter for the next request. You can do something similar with FastCGI, and FastCGI already has the wide availability in cheap ISPs that they say they want. In fact, mod_perl even already has the feature they want with blessed modules that stay in memory: just load them in startup before forking and they will be there already compiled, even with the MaxRequestsPerChild approach.

Why does no one do this with mod_perl or FastCGI? Because the performance is pretty bad compared to letting your code, database handles, and cached data stick around between requests.