Well, we can mark this one as solved. Simple enough, actually -- thanks to Chris and Demian for leading me to water.
The following code works on both Linux and Windows 7: def OnDocs(self, event): """Opens the User's Guide in the default web browser""" fullpath = os.path.abspath('documentation/HTMLDocs/index.html') url_link = "file:///" + fullpath webbrowser.open(url_link) This allows both platforms to have their own idiosyncratic path structures without having to create separate code for each. It even chooses the correct browser! I learned some more about Python today, too. I'd never explored the 'os.' library before, and now I see things a little more clearly. Thanks again, guys! -- http://mail.python.org/mailman/listinfo/python-list