Basic filehandling with flash

Id like to make a graphical editor with flash that has some basic features like copying and moving files, and editing text-files.

The editor is to be used exclusively offline.

I know that AS doesnt provide such functionality, but perhaps its possible with some backend script that doesnt require any installs (like php does)?

Javascript, perhaps? Does it have the power to edit files etc?

Thank you

Btw, it has to be a free alternative. Can only afford flash-license :confused: