SCO-Caldera CEO Darl McBride started attacking the GNU/Linux community last summer, shortly after he took that job from Ransome Love. It also was an attack on Red Hat Linux.
Over the winter, apparently McBride festered in his lack of love for Linux. In January 2003, Maureen O'Gara broke a story that McBride was planning to exploit SCO-Caldera's intellectual properties (IP) portfolio.
Next, McBride announced the formation a new SCO-Caldera project, SCOsource, which would protect and enforce SCO-Caldera IP. Initially, McBride's SCOsource project did not directly attack the GNU/Linux community. Rather it sought to protect SCO-Caldera's UnixWare libraries. This appeared to be a legitimate exercise of copyright protection and enforcement.
Then in March, McBride's SCO filed its now infamous Caldera v IBM lawsuit. What made that Caldera v IBM lawsuit so controversial was that SCO-Caldera needlessly attacked and insulted the Linux kernel, GNU/Linux operating system, Linux distribution, and many other free software developers. All the major GNU/Linux community people, Alan Cox, Gaël Duval, Richard Gooch, Gordon Ho, Richard Stallman, Linus Torvalds, David Weinehall, and more reject SCO and McBride's claims that Linux was derived from Unix and other insults.
Nevertheless, on12 May 2003 McBride and SCO sent a letter to several thousand companies, stating in part:
Linux is, in material part, an unauthorized derivative of UNIX . . . We have evidence that portions of UNIX System V software code have been copied into Linux . . . legal liability that may arise from the Linux development process may also rest with the end user . . . We intend to aggressively protect and enforce these rights . . . we are prepared to take all actions necessary to stop the ongoing violation of our intellectual property or other rights.
That provoked Univention and Tarent to obtain German court orders telling SCO-Caldera and McBride to shut-up -- or face some pretty hefty fines and/or jail time for failing to shut-up.
Red Hat has filed a lawsuit in the United States Distict Court for Delaware to shut SCO-Caldera and McBride up in the U.S.