A startup company is promising to bridge the gulf between desktop and hosted applications with a hosted service that lets Microsoft Excel users make their spreadsheets universally shareable without the usual exchange of attachments.

Currently in beta and due for commercial release on 1 August, Expresso works by providing a secure server and translating Excel elements into a back-end database. Users can collaborate in real time, set hierarchies for access, compare versions and track all changes. The only requirement is a browser and Excel licence and spreadsheets can be downloaded for offline use then synchronised back to the server at a later point.

“Our goal is to enable enterprises to work securely but in an ad hoc manner,” said George Langan, Expresso chief executive. “Ninety-five percent of businesses use Excel for financial reporting, forecasting and just about everything else. There’s nothing wrong with Excel, it’s just the limitation of the desktop. Collaborative spreadsheets have to be open for people to adopt them but very secure also. We want to make [collaborative spreadsheets] as viral as MySpace.”

The Expresso release could be timely for Microsoft as the inherently collaborative nature of web-based spreadsheets has helped firms such as Google and Zoho garner interest in their programs and left the software giant promising to add such capabilities to its own applications.

Another key market for Expresso could be compliance. The service creates audit trails that monitor all changes to spreadsheets, as well as relevant IM and email sessions.

In a paper, Philip Howard of analyst firm Bloor Research wrote that: “The big advantage that Expresso offers is that it is available as a service a la Salesforce.com. Given that leading control and compliance tools typically cost six to seven figures [it] is potentially compelling.”

Expresso plans to offer tariffs from an individual user service at $15 per month to corporate licensing schemes. Next year, Expresso plans to offer similar services for PowerPoint and Word.