ShrinkWrapClassloader allows to load jars completely in memory and attach them to URLClassLoader. this can easily used for the JRubyClassLoader for adding urls dynamically mostly via require "some.jar"

the current implementation just uses file: urls and this just works for all fancy urls (J2EE, OGSi, etc), i.e. any nested jar inside jar gets copied to /tmp and used from there.

the ShrinkWrap framework allows to copy such a jar into memory instead of the filesystem. I am not sure if it is feasible to just load all the jars into memory and use them from there.