For those who know Zope but are not familiar with this..

If you install the ExternalEditor product on your Zope server, then when you're browsing through your Zope system, in addition to being able to edit the files through your browser, you get a little pencil icon beside the objects, which is a link to a .zem file representing that page and how to edit it.
If you click on it, your browser will download the .zem file.

This program understands those .zem files and can use it to grab the file from the server, and pass it to an editor of your choice. (TextMate, in my case). It also monitors the local copy so that whenever you hit save in your editor, it copies it back up to the server. This is very cute.

If you use Safari as your browser, it will just download the .zem file and you'll need to double-click it to get it into ZopeEditManager. If you use Firefox (and some other browsers), you can configure it to open .zem files automatically in ZopeEditManager so it really is as if you're editing the remote file in your local editor with a single click.

I've only done a quick trial, but so far it seems to work nicely.