Just as mod_perl has spawned new development projects, so has mod_jserv and there's another interesting Java-based application engine called Locomotive which ties into Apache with its mod_locolink. Additionally, we occasionally hear of other projects focused on embedding server side TCL, Python, Javascript and ColdFusion. These projects really exemplify the power of Apache's open source community based development model.

If you've not taken the opportunity to yet, peruse the Apache Module Registry at http://modules.apache.org/ -- if there's a functionality you're looking for, there's a good chance that someone who precedes you have had that need as well and has posted a module to fulfill it. Perhaps you can implement the functionality better, the registry does have variations on different module capabilities; not that you should gratuitously reinvent the wheel but there room for many implementations and the Module Registry can point to them all.

So have fun exploring the frontiers of Apache!