Google's coming at Microsoft through Exchange; now Zoho's coming at it through SharePoint.

It's rigged it so SharePoint users can use its online office suite, create and collaborate on documents, spreadsheets and presentations, then save the results directly to SharePoint in Microsoft Office-supported formats.

Zoho applications are served from the cloud, so nothing is installed on the desktop. It's all browser-dependent.

Based on sharing permissions already defined in SharePoint, multiple users can collaborate in real-time. They can chat too.

Zoho says the documents created are saved back to the SharePoint server behind the corporate firewall, leaving no data on Zoho servers.

When the documents are opened, copies are temporarily transferred to Zoho servers. When the documents are closed, Zoho says it's permanently deleted from its servers.

It's available for SharePoint 2007 and 2003 on a 30-day trial for an unlimited number of users. Then it costs $2/user/month on a yearly subscription or $3/user/month for a monthly subscription.