From the wording in the blog post I think that in some of the cases where people redistributed Paint.NET they broke the terms of the license. In such cases the original author is right to feel that his work has been plagiarized. None of my projects have been big enough that this has ever happened to me so I can't really offer any useful advice for what to do. I think it's sad that he chose to close the source though and as a consequence of it I can now no longer (since 2009 actually but this is the first time I've been made aware of the change of license because the last time I was using Windows on any of my own computers was around that time and the last time I installed Paint.NET on one of my computers it was still open source) advice friends and family to install Paint.NET when they are looking for a photo editing program.

I release most of my own code under a license similar to MIT (the ISC license) and as long as the people who are using my code honor the conditions of the license they are free to rebrand it and sell it if they want to or to do whatever else that doesn't violate the license.

Often I feel that if someone is going to redistribute an MIT licensed project with modifications, they should rebrand it. For example say that I wanted to sell copies of FreeBSD as a whole with some of my own patches and modifications. I would not be able to call that FreeBSD without first working out an agreement with the FreeBSD Foundation [1]. The reason for this being that FreeBSD is a trademark of the FreeBSD Foundation and so they get to retain control of it. This is how it should be. This is what I like about the MIT family of licenses, the code is free but the license does not grant rights to use a trademark. When I say rebrand, note that proper attribution is still required.

However, if binaries are redistributed unmodified then I think it should be ok to refer to it by the original name because then that name is an accurate representation of exactly what is being distributed.

Furthermore I think that when just maintaining source changes in a public repo it should not be necessary to rebrand.

Meanwhile, if someone completely stripped my name from something I wrote and they didn't give me the proper attribution, they'd be in violation of the license and therefore the license would be void. If someone is going to use my code, they are going to attribute me in the manner that is set out in the license.

IANAL, TINLA.

[1]: https://www.freebsdfoundation.org/legal/trademark-usage-term...

The MIT license includes a parragraph:

    The above copyright notice and this permission notice shall be included in all
    copies or substantial portions of the Software.

Clearly those copying the software and changing the copyright information (or simply not including the above) were in violation of the licence and could be sued for copyright infringement.

They can also continue doing that too, since changing string of a disassembled binary isn't that hard.

such a shame

> It's even more a shame to see something become proprietary

I wouldn't call this a "shame". A project as complex and significant as GIMP/paint.net may take a lot of time to maintain and to improve. If you can't find a persistent way to fund yourself, turning it proprietary becomes a tentative option. I understand and respect the decision of the developer of paint.net. As open source developers (I am one of them), we are responsible not only for our users but also for ourselves and our families. Everyone has a life after all.