Express Logic Responds to Copyright Infringement Ruling

Express Logic, Inc., the worldwide leader in royalty-free real-time operating systems (RTOS), provided a clarification of the results of its arbitration against Green Hills Software, alleging copyright infringement of its ThreadX RTOS. The arbitration was brought by Express Logic against Green Hills Software in June, 2006, for infringement of Express Logic’s copyright on the ThreadX RTOS, as well as for contractual and statutory violations. Green Hills counter-claimed for defamation and contract violations. Express Logic’s claim of copyright infringement was based on its belief that Green Hills Software had engaged in copying ThreadX API source code contained in Express Logic’s tx_api.h header file during the development of the u-velOSity RTOS. The arbitrators, none of whom were judges, noted that Green Hills did in fact copy the ThreadX API header file, but ruled that their copying did not infringe Express Logic’s copyright on ThreadX. The arbitrators also denied all of the non-copyright claims of both parties.

Arbitration Findings

  1. The arbitrators expressly held that ThreadX (as a whole and including the ThreadX API header file) is an original work and was independently created by William Lamie, and that Express Logic holds a valid copyright in ThreadX.
  2. The arbitrators recognized that Green Hills did in fact copy C source code from Express Logic’s tx_api.h header file, which is part of ThreadX, and which is contained in Express Logic’s copyright in ThreadX.
  3. The arbitrators ruled that copying of “functional requirements for compatibility” and “words and short phrases” does not violate copyright law, and applied those doctrines to render much of the source code in Express Logic’s tx_api.h header file unprotected. Express Logic argued that the source code in tx_api.h is the literal text of the program, and does not constitute “functional requirements for compatibility.” Express Logic further argued that Green Hills copied more than was necessary for compatibility, and finally that Green Hills did not achieve compatibility. The arbitrators agreed that u-velOSity is not compatible with applications written for ThreadX, but still found the copying to be non-infringing.

Implications For the Industry
“We’re shocked that copying of source code and using it to compete with our copyrighted work was not found to be infringement,” commented William E. Lamie, author of ThreadX and president of Express Logic. “We believe that the basis upon which the arbitrators determined that this copying was not infringing would put all software code at risk of being copied without infringement. After all, what software is not made up of ‘words and short phrases?’ As for the ‘functional requirements for compatibility,’ why should anyone be able to copy source code under the guise of compatibility but not use it for that purpose? This ruling seems illogical to us, and would put all software at risk if this reasoning were to be applied in other cases.”

Fortunately, this decision by the arbitrators has no precedential value. Therefore, when and if a court of law hears this issue, it could very well arrive at a different conclusion.

Green Hills Statements to the Press and Web Postings
In a recent article published by EE Times, Dan O’Dowd, Green Hills President is quoted as saying, “Express Logic copied the pSOS API word for word,” for which Mr. O’Dowd called Express Logic’s actions “highly hypocritical.”

  1. Express Logic’s position is clear, consistent, and not hypocritical: Adaptation Layers may or may not infringe, depending on whether they were created by copying the copyright owner’s source code. Many other factors may also enter into the picture, such as whether the copyrighted product is a market leader (as was pSOS at the time Express Logic created its Adaptation Layer) or is facing end-of-life (as was pSOS at the time, as Wind River had just acquired ISI and announced end-of-life for pSOS), whether the copyright holder objects to the use (which Wind River never did), and other factors that might lead to a finding of fair use or consent of the copyright holder.
  2. In the EE Times article, Green Hills accuses Express Logic of copying the pSOS API “word for word.” Express Logic did not copy a single line of pSOS source code in making its Adaptation Layer.
  3. In the EE Times article, Green Hills attempts to defend its actions by attacking Express Logic’s legitimate Adaptation Layers, while the key issue is Green Hills’ u-velOSity API. Legitimate Adaptation Layers may benefit the industry by providing compatibility across different operating systems. Green Hills achieved no such compatibility with u-velOSity, which the arbitrators noted is not compatible with ThreadX, and so Green Hills’ reference to Adaptation Layers is irrelevant.
  4. Green Hills currently markets u-velOSity on its web site as being “The Most Intuitive Royalty-Free RTOS” and says explicitly that “…u-velOSity offers a clear, concise API that reduces development time and improves product maintainability.” Green Hills does not mention that the u-velOSity API is a thinly-veiled copy of the ThreadX API.

Why Did Green Hills Copy the ThreadX API for u-velOSity?
To the best of Express Logic’s knowledge, no other company’s API was ever copied for use in a competing product without attribution. Why would Green Hills copy the ThreadX API if not to provide compatibility with applications written for ThreadX? Why did Green Hills not just use their own velOSity or INTEGRITY API for u-velOSity?

“I find it ironic that a company that proclaims itself a technology leader would copy code from a partner’s API instead of writing it themselves,” commented Mr. Lamie. “Shouldn’t a technology leader be developing new code that others envy and emulate, rather than following on the heels and hard work of a smaller business partner and copying their creative code?”

The ACM Code of Ethics
Indeed, the American Computing Machinery Organization (ACM) publishes a code of ethics that it expects its members to follow. That code specifically calls on computing professionals to give proper attribution:

“1.6 Give proper credit for intellectual property. Computing professionals are obligated to protect the integrity of intellectual property. Specifically, one must not take credit for other’s ideas or work, even in cases where the work has not been explicitly protected by copyright, patent, etc.”

Mr. Lamie concluded, “While we would have preferred to avoid the distraction of litigation, Express Logic is committed to protecting its intellectual property. When we first saw the u-velOSity API, we realized we could not leave the copying we suspected unchallenged. While we are disappointed that the arbitrators chose to deny the relief we sought, we feel vindicated that the tribunal did recognize the copying that occurred.”

About Express Logic
Headquartered in San Diego, CA, Express Logic offers the most advanced run-time solution for deeply embedded applications, including the popular ThreadX(R) RTOS, the high-performance NetX(TM) TCP/IP stack, the FileX(R) embedded MS-DOS compatible file system, and the USBX(TM) Host/Device USB protocol stack. All products from Express Logic include full source-code and have no run-time royalties. For more information about Express Logic solutions, please call 1-888-THREADX, or email inquires to

ThreadX and FileX are registered trademarks, and NetX, CANX, USBX, preemption-threshold, picokernel, UDP fast path technology, are trademarks of Express Logic, Inc.