A recent move by the SCO Group Inc. promises to make Unix ELF code as well-known in IT circles as Orlando Bloom's portrayal of the Lord of the Rings' elf prince, Legolas, is with teenage girls.
SCO has added Unix Executable and Linking Format (ELF) codes to its lineup of alleged copyright infringements in its US$5 billion lawsuit with IBM Corp.
"ELF is a standard file format, which is currently used for dynamic linking, dynamic loading, runtime control, and shared library creation in UNIX," said Marc Modersitzki, spokesperson for SCO in Lindon, Utah.
This binary format is absolutely crucial to the running of Linux and without it, Linux would not be able to work, said Brian Zammit, co-founder and vice-president of Systems Aligned Inc., a Linux consulting company, in Brampton, Ont. It's essentially the glue that holds it all together.
"ELF is one way of arranging data in a compiled program, though there are other methods (such as a.out) to arrange data in a compiled program but they are mostly reserved for backward compatibility," he explained. "Most programmers moved to ELF several years ago."
Developed in the 1980s by Unix System Laboratories, ELF is comparable to Microsoft Corp.'s Dynamic Link Libraries (DLL), Modersitzki said. Its functions include identifying, parsing and interpreting object files. The three types of ELF files are executable, relocatable and shared object, he added.
SCO's vice-president of engineering Sandeep Gupta first singled out ELF as a possible infringement, however the filing outlining further details has been sealed but the alleged ELF infringement was initially alluded to in a SCO court filing from July 8 entitled Declaration of John Harrop in support of SCO's opposition to IBM's motion for partial summary judgment, Modersitzki said.
ELF joins other SCO alleged copyright infringements of Unix including Read-Copy-Update (RCU), System V in Linux 2.6, user level synchronization routines, System V IPC code in Linux 2.2.20 and Unix header and interfaces.
One industry watcher, Gordon Haff, senior analyst and IT advisor from Illuminata Inc. in Nashua, N.H. said SCO's ELF claims do not stem from direct copying as in the case of the System V code allegations but instead stems from a charge on a copying of concept.
When SCO initiated its lawsuit against Big Blue, it focused on three different areas.
"One of the was literal copies, the second was Linux being a derivative work of Unix and the third was sort of a vague-ish methods and techniques," he said. ELF falls in the methods and techniques area.
Haff said this is a complex area to make judgments on because there is a great deal of similarity of methods in all operating systems, despite the existence of software patents, which protect against the copying of methods.
For example, Microsoft Windows owes a great deal to Virtual Memory System (VMS) because Windows employs similar concepts and techniques, he said. But because concepts are re-used over and over in the computing industry, the ELF case would be difficult to win.
Most of the attention on the SCO lawsuit has been around literal copying because it's a lot easier for people to comprehend, he noted.
"Most people understand and acknowledge that to a degree that if there have been big blocks of code that have been cut and pasted into Linux, then that was a bad thing," Haff explained. "As this has turned out there wasn't much of that — there was some — and there were certainly issues over what was lifted and whether that had been released under a [Berkeley Software Distribution] BSD-style license by Caldera." SCO was formerly known as Caldera.
As such, Haff said whether these infringements are enough to let SCO win the case, is up to a judge.