Ghost is founded on the passionate belief that the Windows and Mac model of your operating system — with your precious applications and data all walled inside one physical computer — is obsolete, says Ghost’s creator, Zvi Schreiber.

The Global Hosted Operating System, or Ghost, is the logical next step in a trend to move applications and files from client computers to the Internet, says Schreiber. It is a Web-hosted image of your desktop or laptop — a virtual computer that can be accessed by any client device via a Web browser.

Ghost doesn’t require software upgrades or patches for user machines, and it’s always backed up. But its key selling point is the mobility and device-independence it offers users, says Schreiber, CEO of start-up Ghost in New York. "Young people do a lot of computing at school, and business people don’t want to carry their laptops everywhere," he says. "People want to get their computing environment from anywhere."

Offered as a set of application services inside a virtual computer, Ghost is free for users. Schreiber says revenue will come from vendors who remit fees to the company when they sell products or services to Ghost users.

Ghost is in an alpha, "open to the public" release, Schreiber says, and it’s available. “We don’t feel we are offering a complete service by any means, mainly in terms of the number of applications that are nicely integrated into Ghost,” he says. “But that’s changing pretty rapidly. By the third quarter, it will be a beta [release]. Not perfect, but really usable.”

Ghost users can’t use client-based applications like Microsoft Word or Excel, but they can use Web-based alternatives such as Google Docs & Spreadsheets. Schreiber says over the next year or so, he will seek partners to create Web-hosted versions of all popular desktop programs and help users migrate their data to them.

Rick Boyd, a Catholic priest and self-described "computer nerd," says he uses Ghost to host and manage his bookmarks, files and documents. "I use it every day, and I find it very convenient," he says. "I believe that Web-based applications are the future."

Boyd says he likes being able to access his bookmarks from any computer, no matter where he might be. "But it’s not just a bookmark manager," he says, "it’s a virtual desktop, and that’s very innovative."

Ghost is built from OpenLaszlo, an open-source platform for the development and delivery of Web applications that have the appearance and functions of traditional desktop applications. Ghost is hosted by Amazon Web Services.

Despite the use of OpenLaszlo and Amazon, Ghost developers still had to write a fair amount of software and do considerable systems integration work, Schreiber says.

"We had to think about the architecture very carefully to make it scalable, robust and secure," he says. Scalablility was enhanced by pushing some of the processing and memory use from the server to clients, Schreiber adds.