I don't know how to switch the compiler, but lLooking at the source, I
see that janino uses ClassLoaderIClassLoader,
http://fisheye.codehaus.org/browse/~raw,r=1.6/janino/janino/src/org/codehaus/janino/ClassLoaderIClassLoader.java
which in fact uses a reflection-based loader.

I believe I had already pointed out the problem with using reflection
to resolve external references: it can lead to unexpected first active
uses (in other words, using a class as a reference in compilation
could trigger the class's static {} initializer.) which may or may not
be tolerable (if the class is already loaded or has no static
initializer, it's not a problem - otherwise, it's a nightmare.)

In any event, this is all besides the point (at least the point I was
trying to make). I argue that a sound design should separate runtime
and compilation classpath (or at least provide the option of doing
so), but I acknowledge that the current approach is pragmatic and
probably works for a large number of cases.

To return to the original point of discussion, I'm wondering how to
make it easy for different .drl files to refer to each other. You had
brought up the Rule Agent, though it wasn't clear to me whether you
meant that the rule agent implementation as it currently exists
already has a way of specifying such dependencies, and if so, how - or
whether you are consider this a future addition.

>From my (admittedly brief) examination of the the rule agent, it
appears to be a tool that monitors filesystem or network-based sources
of rules in pre-compiled packages, then loads them.  What I am seeking
is a simple way for one rulebase to refer to a set of classes and
rules on which it depends, similar to how, for instance, an XML file
can refer to an external DTD or Schema.