SCO Group has sent cease-and-desist letters to select US Fortune 1000 companies charging them with illegally using more than 65 SCO-owned Application Binary Interfaces (ABIs) without permission.
The move was part of SCO's groundwork-laying for a potential copyright infringement case against Linux. The 19 December letters claimed that the ABIs that allow customers to run Unix applications over Linux are owned by SCO and were used without the company's permission.
In the letter, SCO cited more than 65 examples of what it claims are improper use of ABIs and header files in current Linux distributions.
The move came as Novell worked to intercept SCO's claim by registering for copyrights on several versions of Unix System V with the US Copyright Office over the past quarter.
Meanwhile, Linux kernel creator Linus Torvalds characterised SCO's latest intellectual property (IP) claim as technically baseless.
Nevertheless, in SCO's letter and in a conference call held in the US to detail its latest IP claim, SCO insisted that use of its IP by Linux customers in a commercial setting violated company rights according to US Copyright Law and the Digital Millennium Copyright Act (DMCA).
'Certain copyrighted application binary interfaces have been copied verbatim from our copyrighted Unix code base and contributed to Linux for distribution under the General Public License (GPL) without proper authorisation and without copyright attribution,' SCO wrote in the letter.
'The Unix ABIs were never intended or authorised for unrestricted use or distribution under the GPL in Linux. And distribution of Linux by a software vendor or redistribution of Linux by an end user that contains any of the identified Unix code violates SCO's rights under the DMCA,' the letter concluded.
This latest claim, separate and distinct from the contractual violation charges that SCO filed against IBM last March, maintained that the use of the ABIs by customers--and vendors--violates SCO's copyright rights.
SCO has not yet proved any claims against Linux in a court of law.
A SCO spokesman also said the company had sent out hundreds of letters to Unix licensees demanding they certify in writing that each licensee is in full compliance with the AT&T Unix source code agreement. SCO has about 6,000 licensees.
One spokesman dubbed the move an 'audit'. SCO has claimed that customers could be subject to fines of $30,000 for each instance of innocent infringement and up to $150,000 fine for willful infringement.
In a US conference call, SCO CEO Darl McBride has said companies could avoid penalties by ceasing use of Linux, removing the offending files from the Linux software they use or by paying SCO a licensing fee.
SCO made a distinction between what it dubs proprietary ABIs and application programming interfaces (APIs). The company acknowledged that some APIs were made available through POSIX and other Unix open standards but alleged that the binary interfaces were protected under its ownership of Unix System V.
In an e-mail to CRN in the US, Torvalds, a fellow with the Open Source Development Labs, alleged SCO's latest series of allegations were hollow and that the so-called violations relate to a group of simple header files, not significant IP.
'It's basically something like five files, it's just that several of them are replicated for every single architecture out there,' Torvalds wrote. 'And the thing is, those files don't even contain any code.'
'They contain things like the error number lists--and, yes, we made the error numbers match with traditional Unix on purpose, since, for example, Linux/alpha wanted to be binary-compatible with OSF/1. Ask any programmer what this is, and he'll tell you it's just a C header file that gives symbolic names to static error numbers,' he wrote.
Torvalds also said Novell's attempt to contest SCO copyrights muddies the waters.
McBride acknowledged that filing a case against an end user was an unpopular and aggressive tactic. But he alleged that IBM, Red Hat and others had exposed their customers by hiding behind the GPL.
'Everyone points to a clause where they don't have liability, they are pushing the liability down to the users,' he said.
Meanwhile, SCO narrowed its losses during its fourth fiscal quarter to US$1.6 million from US$2.7 million a year ago, although it would have reported a US$7.4 million profit in the quarter before the US$9 million in legal fees it paid out to fund its expanding litigation.
The price tag could get higher as SCO opponents gird for legal battle.
According to the Groklaw Web site, which chronicles the legal aspects of SCO IP cases, Novell has registered for the copyrights on Unix System V 2, 3.0, 3.1, 3.2, 3.2/386, 4.0, 4.1, 4.1ES, 4.1ES/386, 4.2, and 4.2MP with the US Copyright Office in the past four months.
Novell's planned acquisition of SUSE Linux would make it--along with Red Hat--subject to copyright infringement since both vendors provide Linux distributions on the market.
By early January, SCO must provide IBM attorneys with the Journalling File Sy