San Francisco, Aug 06: SCO Group, which claims its blueprint for Unix software is embedded illegally in versions of the free Linux operating system, unveiled on Tuesday details of a controversial licensing plan for companies using Linux. The plan, which will initially cost $699 for a computer with a single central processor running Linux, has irked advocates of the software operating system. Unlike Unix or Microsoft's Windows, Linux can be copied and modified freely.

SCO, based in Lindon, Utah, sent shock waves through the ranks of Linux users in March when it sued IBM for $1 billion, charging that the world's largest computer company had taken parts of the Unix code and introduced them into Linux, violating SCO's intellectual property rights.

Linux is supported by a far-flung network of programmers sharing software code. Because it can be obtained for free, Linux has caught on with companies seeking to lower technology costs. It competes with Microsoft in the market for server software for managing computer networks. Many of those programmers are gathered in San Francisco this week for the LinuxWorld Conference and Expo, one of the industry's largest gatherings.

SCO said its Linux licensing plan is a one-time fee that customers can pay to avoid infringing on SCO's intellectual property rights. The price will double at the end of an introductory period that ends on October 15.

Licensing terms for computers with multiple processors will be posted in detail on SCO's Web site (http://www.sco.com), said Chris Sontag, SCO's senior vice-president in charge of its intellectual property and licensing efforts.

Shares in SCO have skyrocketed from their March level of around $3, The shares rose 41 cents, or 3.4 per cent, to $12.49 in Nasdaq trading on Tuesday. Bureau Report