Execution of a "long" script

[jbv at souslelogo.com]

Hi list
I'm about to launch a script on LC 6.5.2 on Mac to process a large xml file,
and the execution will take several hours at least.
I am wondering : if I use other apps like a browser or a mailer after
starting
the script, or if I return to the Finder or navigate through various apps in
the dock, what happens to my script ? Is it slowed down or even stalled while
I use other apps, does it still run as a background task, or... ?

Thanks
jbv