Like the Byzantine Empire before it, IBM has cast another bronze tube meant to spit Greek fire at Microsoft and break its siege of the desktop.

The ingredients this time consist of Canonical's Ubuntu operating system and Virtual Bridges' Virtual Enterprise Remote Desktop Environment (VERDE) 2.0 larded with IBM's own Smart Client desktop software otherwise known as Lotus Symphony, Notes and Lotus applications, basically e-mail, word processing, spreadsheets, unified communication and social networking.

Together they form the Open Virtual Client Solution (OCCS).

IBM started this particular cloud-based repulse back in December with the announcement of a Virtual Bridges-based VDI solution. Since the push started in March they're reportedly wracked up an 800,000-seat pipeline, with 30,000 seats inching toward production.

Now they're added an offline offensive or, as Virtual Bridges calls it, a "disconnected desktop."

VERDE 2.0 creates a virtualized desktop that can be used when disconnected from the Internet.

The trick is in integrating a lightweight, client-side KVM hypervisor based on a new Self-Managing Auto Replicating Technology (SMART) protocol.

The SMART protocol synchronizes a replicated cache running on the client-side hypervisor with the managed image on the server, the same image used to populate VDI sessions.

Virtual Bridges CEO Jim Curtin claims the ability to manage disconnected users alongside VDI users "moves the state-of-the-art beyond VDI to really becoming Desktop Management Infrastructure."

What VERDE 2.0 can't do yet is sync the data - because it takes too consarned long - so it comes down to a choice of the VDI version or this newfangled VERDE 2.0 stuff.

Virtual Bridges, however, has another snare. It can virtualize and manage Windows as well as Linux guest desktops - the user blithely unaware it's running on Linux.

IBM is pushing the Microsoft-free virtual desktop as a cost saver - saving money being a user hot button right now - but the vast majority of users still clings to Windows and Office.

If the user isn't willing to go whole hog on a Microsoft alternative, IBM will argue that organizations can realize the benefits of VDI, whether they move to Linux desktops or not, but they might as well sprinkle a few, say, "experimental" Linux desktops around in some user segments and gain the additional cost saving.

It figures the creep could become customary.

IBM's VP of Linux and open source Bob Sutor encapsulates IBM's position.

"The cost advantages of moving even a modest segment of users to Linux," he says, "are very attractive, and virtualizing the desktop delivers even greater cost efficiencies and easier IT management. In today's economy, it's smart to investigate Linux on the desktop and Virtual Bridges' VERDE is a great way to do it."

The Linux back-end means a low price point and the architecture is inherently scalable.

Virtual Bridges CEO Jim Curtain says his widgetry can support a million users. He gets 100 users to a server and with his Cluster Master middleware can support 10,000 servers. However, IBM means to move the whole megillah to its trusty mainframes eventually.

VERDE pricing is $50 per seat a year for 1,000 seats or more. By comparison VMware's View 3 runs $250 a user.

Like other VDI solutions, VERDE provides protection against viruses, malware and other damage when users are disconnected. If a session is corrupted by malware, the user can restart the session and the session is launched from the write-protected replicated cache of the managed image, on the local disk. This ability eliminates help desk intervention and makes the environment virtually malware-resistant.