I want to port routines from some open source software to another programming language and distribute it publicly. The source code is licensed under GPLv2, so this should not be a problem. However, the following statement on the website irritates me:

Important: [the algorithm] is under a patent by the [...] and any commercial product using this type of algorithm (or the recompiled binary files distributed here) should contact the [...] patent office.

How does such a patent affect me as developer? Am I allowed to modify/redistribute the sources? If yes, do I have to include that patent statement?

2 Answers 2


Patents are about structure and function not about snippets of code. If you produce a product that does all of the steps of an enforceable patent then you are infringing. Does your code contain portions of somebody else's code? Patents don't care (copyright does). Does your code, however put together, do all of the steps of a particular claim of a particular patent is the question.

The open source project may practice a patent by doing actions a, b, and c. If you do a, b, and c with or without portions of that software then you infringe. If you take all of their code, rearrange it and produce a program that does a, b, but not c, then you are ok.

In this case the patent owner seems to be saying that the patents they own that the code infringes on can be practiced non-comercially.

  • Ok, so this means that it does not matter if I use their code or reimplement the algorithm on my own; the patent is infringend either way. If I made the source code available, would it be my responsibility to warn users of a possible patent infringement?
    – MB-F
    Dec 19, 2013 at 18:16
  • If you know what patent or patents are involved you might find that what you are planning doesn't fall under any of them.
    – George White
    Dec 19, 2013 at 18:55
  • I suppose the best way will be to go and ask the holder of the patent. Am I legally allowed to provide source code for public download that infringes on a patent?
    – MB-F
    Dec 19, 2013 at 19:05
  • A patent grants the patent owner the exclusive right to "make, offer for sell, import and use". Also there is contributory infringement and inducing others to infringe. I would guess you would be making it and you would be inducing others to use it. Presumably your downloaders would compile it - that is probably making. A bigger problem is that the patents owned by the entity involved may not be the only owners of patents you might step on in producing your final result.
    – George White
    Dec 19, 2013 at 22:14

If the software you are creating does not infringe up the claims of the patent, and proves novel / uniqueness or even obviousness, then you should be ok. However, contact a patent attorney first! Software / Method patents have proven the new Gold Rush on American Businesses. Methods / Software patents are dangerous, so watch out!!

Likewise, do a search of that patent number in the USPTO or Google Patents and check citations / references mentioning that patent and use keyword searches that are used within your technology. For example "Clamps, database, upload" and such.

Remember, patents are about the CLAIMS. If you infringe upon one or more claim of a patent, then you risk getting sued.

Hindsight is not 20/20 when you get sued for patent infringement. You must do as much homework as you can up front because not knowing is not good enough. A Patent Holder / Patentee can get away with not knowing about prior art, but you can't get away with not knowing about their patent. Its that miserable when you get sued.

My advice is to set aside substantial funds to fight lawsuits against patents and also be prepared to pull the plug at any time. The less assets you have in your company, the less the patent holder can take. This is why we have so many "startup companies" built by experienced, previous business owners.

Be prepared. You can't win a patent infringement lawsuit unless you're a huge company or filthy rich. The software you may be building is great, but if it infringes, it will be short lived.

Finally, if you have found prior art, such as an enforceable patent, you may want to contact the patentee start looking into licensing options. Most of the time, licensing agreements come from lawsuits, and they are usually in favor of the patentee because they whittled you down via a patent lawsuit and have you backed into a corner and seem to have leverage on you at this point.

The most important advice is to seek assistance from a patent attorney, usually at astronomical costs

Get ready to be double-taxed on your innovative idea!

  • How novel your product is has no bearing on whether or not it infringes someone else's patent.
    – George White
    Dec 19, 2013 at 17:44

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