SCO to show code, possibly sue Novell

According to an article on CNET, SCO is planning to start showing some if the disputed linux code under NDA to outside analysts.

Further, the company has stated that it is turning the issue of disputed ownership of UNIX to its attorneys.

It certainly makes me wonder, though, if the problem is that IBM put some of the UNIX code in to Linux (an operating system for which source is already available), why would they demand an NDA to look at the parts they claim are copied. And, what will the terms of the NDA be?