SCO says proprietary source code underlying Unix has been illegally copied into the Linux kernel. SCO critics argue that because the company shipped a Linux product under an open-source license ...

The software maker's agreement to license Unix lends weight to SCO Group's legal claims of copyright violation and helps Microsoft do battle with Linux.

The SCO Group has secured U.S. copyright registrations for Unix System V code and now intends to begin charging customers to run Linux.