If by a filesystem you mean a directory system for perl to live in. I don't know about the other stuff, but this just struck me....
After looking at this page I had an idea. If there is a version of zlib for PalmOS and zip files can have filesystems (or at least directory structures) so why not have a PalmOS app that calls the zlib to dynamically unzip what you need, this would cut down on the physicaly space need for perl (but increasing the swapping needed in RAM, bite me).

I have no idea at all how you would implement this, but it would be cool if it worked :)

I know that Plucker, a perl app, uses zlib on the palm to load web pages downloaded from you PC.

The Evil but Fickle Dr Lambado
In the Kingdom of the Blind, the One Eyed Man is King