I'll reply on the assumption you posted the above in good faith. The article is talking about patents, not copyright and it's important to distinguish between

I'll reply on the assumption you posted the above in good faith. The article is talking about patents, not copyright and it's important to distinguish between the two. I didn't read the article in detail, but basically it's saying that if you allow Alice to use a patent in a piece of software and you allow Alice to distribute that software to Bob, that you can't now come after Bob for using the patent in the piece of software -- because the patent has "exhausted". I'm not entirely sure this will hold up of Bob makes a derived work of the software, but I suppose it might. It's an interesting thought. Anyway, on to your questions, which seem to have little to do with the article: "Does this mean that MongoDB and others who have changed their licenses to be 'everyone but cloud providers can do this for free' is not able to do that because the work has been presumably licensed?" No. They can make any kind of copyright license they want. There is no exhaustion for copyright. Just because I grant Alice a license to the software doesn't mean that I have to allow Alice to give it to Bob. In fact, I can make a license that forbids Bob explicitly, but allows Cathy to get a copy. I can even write a license that disallows people who look like Bob (unless that is discrimitation in a protected category) from getting a licence from Alice. Incidentally, I could do that with a patent as well, but the situation they are talking about is Open Source licenses. Open Source licenses are, by definition, licences that do not allow you to restrict who Alice can distribute the software to. MongoDB people would like to redefine what Open Source means, but until they do, their license is not Open Source. Question 2: [I am building a hardware/software project that relies on Open Source software]. "Is patenting my work okay? What parts?" You can patent any parts of your project that you want. However, some of the software included in Arduino contains a patent licence. Your software may or may not use that software. Pay attention to the license that you use for your software. If you are using a license like the GPLV3, then you are granting a patent license with the software. So this means that if the software contains patented parts, you are granting a license to the downstream user for that patent. If you don't want to do that, then don't choose that license. If you are choosing that license because you it allows you to cheaply use software that other people have written, then too bad for you. You'll have to write that software yourself. That's the price of the software: take it or leave it. It's your choice. Now, with respect to the suggestion in the article: if you choose to write your software using an Open Source license that does not have a patent grant, will you end up essentially giving a patent grant due to patent exhaustion. Maybe. I'm not a lawyer, but it's an interesting possibility. Again, same advice: if you don't want to, then don't. But don't complain that your non-Open Source options are too expensive.