Adventnet, whose Zoho browser-based productivity apps make it the most interesting and industrious little company in the world of Web services, is rolling out an update to its Zoho Writer word processor today, and it's a biggie: The company has used the Google Gears extension for Firefox to let you edit documents in Zoho Writer even when you don't have a live Internet connection. (Zoho Writer has supported Gears since August, but until now, you've only been able to view documents when offline, not make changes.)
Once you've installed the Gears extension, taking Zoho offline is pretty simple. When you're ready to disconnect--say, because you're about to get on an airplane--click the "Go Offline" link above your document. Zoho will copy the document locally, and you'll be able to edit it, although not all features are available offline. (Preview mode is disabled, for instance, as are tools for exporting documents to different formats.) When you've regained connectivity, clicking "Go Online" will shuttle your edited document back to the Zoho servers.
I've tried offline editing enough to verify it works, but haven't yet taken any shared documents offline, so I'm not entirely sure how Zoho handles collaboration when offline editing is in the mix. Presumably, taking a document offline should prevent colleagues from editing it, so you don't end up with multiple versions of a file that can't be reconciled.
Zoho's productivity apps represent the most formidable competitor to Google's own Google Apps suite, and while Google's offerings trump Zoho's in some respects, Adventnet has a remarkable track record for rolling out new features before Google does. I'm dead certain that Google is working on a version of Google Docs that lets you edit word processing documents offline, but Zoho has this important feature right now--and it did it with Google's own Gears technology.
Here's a video from Adventnet that explains Zoho Writer's offline features.