I'm starting to learn Ruby, and I've decided on a small web/integration 
project.  Naturally, I've got a few questions.

1) Is there a recommended framework for web-based applications?  I seem 
to recall hearing about an Enhydra XMLC clone in Ruby.
2) What's the best way to access (Linux) system-level calls. 
 Specifically, I'll need mount/umount, and I'll need to be able to send 
SCSI commands.
3) Is there a package/class for JPG manipulation?
4) Is there a package/class for manipulating files on the file system 
(move, copy, delete, rename).

Thanks much.