No apologies, no compensation for building a commercial product on something I had spent a decent amount of time on. Very disappointing of them.
At the time, we had a student working on the project and they used a couple of classes from NProf code for loading the profiler under IIS. This was done incorrectly as it was not in compliance with the GPL license. This was brought to our attention on March 18th 2005, and after careful examination we responded on March 21st 2005, following up by removing said code and rewriting it. We indicated this resolution to you and you were satisfied and showed support for JetBrains. We do have reference to the aforementioned interchange between yourself and JetBrains. Should you require a copy, please let us know. We'd like to apologise for this mishap which was a complete oversight, and was remedied as soon as it was brought to our attention.
Feel free to reach me out if you have any further questions
Apologies on my end for mis-remembering that I already received an apology from the VP of product development at the time.
That would be great - I no longer have the email in question as I lost access to that account and virtually all email records from the early 2000s (mmastrac@canada.com, I'm assuming). If you could forward that to matthew@mastracci.com I can have that for my records so I don't forget the details again.
I think the important question here is did they do this in violation of the open source license you had adopted as at the time the alleged infraction took place?
Think about it this way: When Linus started working on Linux and decided to release it under the GPL, was it because he wanted companies to use it as the basis of billion-dollar revenues without sponsoring development or compensating him for his work? Lots of people start contributing to open source at a smaller scale, where it's just individuals and small businesses and non-profit orgs sharing with each other, but it becomes kind of a different matter when a company has dozens or hundreds of millions to throw around and doesn't share back. At least in the case of Linux it is well-funded now but there are other cases where core infra has still suffered - you can find recent stories about how the maintainer of NTP struggled to pay rent even though massive companies rely on it.
I chose to approach this with an economic lens, hence the question of whether the original license was permissive, which is the green-light that allows all commercial exploitations to not appear illegal in the eyes of the law.
Open source is one of those activities where developers, who are no less human than non-developers, interleave social norms with market norms.
As far as humans go, social & market/economic norms don’t mix very well [0], so an unfortunate side effect of a lot of open source projects is that our expectations as humans get routinely violated due to the unnatural mix, as your example of the open source NTP developer in near penury clearly illustrates.
[0] https://www.aglobalreach.com/wp-content/uploads/2015/04/Soci...
In my case I built and maintained my software for 3 years and when I chose my license I knew the license meant that someone could repackage it and sell it. That was a decision I made, and maybe my decision was wrong, but in the end the economic factors meant I could no longer pay rent by doing it anymore, so I stopped. Those actors lost the foundation of their product as a result, so the economic factors didn't end up working out in their favor either.
I could perhaps have prevented their actions by using the GPL, but it wouldn't have suddenly made them pay me - they would have just lifted someone else's inferior permissively-licensed solution, because there were multiple options and mine was just the best. I did previously have corporate sponsorship, but that never lasts forever.
If you want money then ask for it. Offer a product or service. There are dozens of licenses to choose from.
EDIT: it was clearer than I thought - v0.4 [1] has an explicit GPL 2.0 COPYING.txt in the root.
[1] https://sourceforge.net/projects/nprof/files/OldFiles/nprof-...
For anything that had no license spelled out, they had and have no license to use it at all.
To be clear: they appear to have no license to distribute your code today, and owe you damages for all the distribution they have done thus far that was not licensed.
If you're at all interested in doing anything about it, copyleft.org has a bunch of useful resources.