Paint.NET is great, too. It's not open source, unfortunately (for valid if regrettable reasons), but it's free as in free beer. The memory of its GUI makes me sigh a little whenever I open GIMP.
I use photopea.com. It's a Photoshop clone but loads much faster and works great for when you don't need some of the newest / cutting edge PS features and don't work with large files.
> Initially, Paint.net was released under a modified version of the MIT License, with the exclusion of the installer, text, and graphics. It was completely open-source, but because breaches of license, all resource files (such as interface text and icons) were released under a non-free Creative Commons license forbidding modification, and the installer was made closed-source. Version 3.36 was initially released as partial open-source, but Brewster later took down the source code, citing problems with plagiarism. In version 3.5, paint.net became proprietary software. Users are now prohibited from modifying it.[1]
Paint.NET was open source, but a pirate would download the code, put their name over the author’s, and click build. That’s a very clear case of copyright violation, but the author decided it wasn’t worth the effort (especially if the pirate is in another country).
TL;DR They used a MIT licence and other people were selling broken, rebranded cashgrab copies without changing things like the installer or crash logs being sent to the author etc
It's more than frustrating to have crash logs that don't refer to your code and contain access tokens or similar data because the author of the 'rebranded' software doesn't care about user privacy.
Apparently the author was unhappy with someone re-releasing the software while erasing the original credits (multiple times?): <https://stackoverflow.com/a/1693549>. Not sure why hiding the source code would help much, but oh well.