SCO's letter of warning to certain Linux users claims that "Certain copyrighted application binary interfaces (âABI Codeâ) have been copied verbatim from our copyrighted UNIX code base and contributed to Linux for distribution under the General Public License (âGPLâ) without proper authorization and without copyright attribution."
Here is McKusick's reaction to the SCO claims as evidenced in SCO's letter as published by LWN.
The argument that SCO is making is that they own the ABI, for example
that EPERM (Operation not permitted) will have the value 1 (as defined
in /usr/include/errno.h). AT&T made the same argument with BSD. In the
end we argued that these interfaces had been distributed without
copyright notices in *all* binary distributions which were available
without signing non-disclosure agreements. The conclusion was that
Berkeley could distribute these files with the following notice:
* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
Linus Torvolds says that he typed in these files from scratch and I believe
that he did. Unfortunately that does not get him out of the ABI argument,
because, by necessity, he had to use the same names and values. Thus, I
am guessing that Linux can distribute these files, but only with the above
notice. It is not clear to me whether it would be permissible to also add
the GPL to the above set of notices.
The tangled web of translucent IP claims spun by SCO is further complicated by the fact that they may not even own the copyrights they claim have been infringed upon. Novell, the company from whom SCO bought Unix, disputes SCO's ownership of those copyrights. Both Novell and SCO have filed for those copyrights during the past year.