[Zope] Running a process in the background

[Will Smith]

I currently have a zope product that can download files from another 
server.  The only problem is that while the file/files are downloading 
the web client is stuck looking at nothing.

My goal is for the user to be able to click the "do download" button. 
At this point the user is given a status page that says "download 
running" and then be able to continue using the site.  Since I know the 
filesize before the download starts I would love to able to do a status 
page "download 58%".

Another caviate to this process, is that it needs to be able to run on 
Linux and Windows.

I realize this is really a python specific question, but was hoping that 
someone has implemented something similar on thier zope site.

Thanks in advance
Will Smith