> That's because the side letter that I read > only released IBM from "concepts" not > derivative works, even methods remained > enforced. http://www.sco.com/scosource/ExhibitC.qxd.pdf "2. Regarding Section 2.01, we agree that modifications and derivative works prepared by or for you are owned by you. However, ownership of any portion or portions of SOFTWARE PRODUCTS included in any such modification or derivitave work remains with us. [...] 9. [...] Nothing in this agreement shall prevent LICENSEE from developing or marketing products or services employing ideas, concepts, know-how or techniques relating to data processing embodied in SOFTWARE PRODUCTS subject to this Agreement, provided that LICENSEE shall not copy any code from such SOFTWARE PRODUCTS into any such product or in connection with any such service [...]" So IBM retains ownership of derivative works. If those derivative works did not contain any UNIX code (not developed by IBM), IBM would be free to use them elsewhere. Also, IBM is free to use UNIX techniques (methods) as well.