He also created QuickJS, that's javascript server side, like NodeJS but much faster to start programs. Just type "qjs your-script.js". I use it in my server because of its low overhead to start and run my microservices. https://bellard.org/quickjs/
The productivity of Bellard is truly admirable.
I also wonder his employer might be the nicest do-whatever-you-want-in-your-free-time employer on earth.
Not only that, I wonder what kind of day-job roles he has since I assume there is significant cognitive load in his personal projects (we still think he's a human not a superhuman right?).
For context, my last employer was "Oh you're doing something in your free time? let me utterly destroy you." (and they did).
edit: Even then, now he probably has the world's nicest co-founder instead. Who does cognitively demanding open source software projects made available for free online, while running a startup?
How could they? And what was their motivation for doing this?
An employee doing something in their free time is a rare and valuable asset.
They also had a policy that everyone should spend at least 4 hours every week (outside of the 40 hour work-week) doing some personal project, or learning. The more the better. (it was a recommendation, not a requirement, and there was no monitoring).
Well what I had in mind was a bit more ambitious than four hours. It did not infringe on their bottom-line (I wasn't using their tech or competing with my day-job; it was completely unrelated). But for me they were like "Oh, no, no ... we were just kidding. We really didn't mean that you should do something in your free time".
The encouragement to do something in free-time is a lie! ... they know most of the engineers don't do that. But if someone actually does something, then the lie gets exposed.
Try it yourself. Take them up on their offer and see what happens.
You said they destroyed you.
Did they fire you for working on your project?
Were you harassed? (tall poppy syndrome?)
With success comes maturity, and a startup turns into a corrupt, org-chart, white-elephant company. 90% of the employees end up being cronies that are pushing paper. The remaining 10% are the real engine of the company (cz the revenue stream has to be maintained somehow and real work still needs to be done). But those 10% need to be kept under the thumb at all cost, made to feel they're not good enough no matter what they do; otherwise they might start questioning wtf's going on in the rest of the company. Let's just say that I was one of those 10%. They did whatever they had to do to make an example out of me. I got my freedom, but I actually feel worse for the other hard-workers who were left behind.
* Small and easily embeddable: just a few C files, no external dependency, 210 KiB of x86 code for a simple hello world program.
* Fast interpreter with very low startup time: runs the 75000 tests of the ECMAScript Test Suite in about 100 seconds on a single core of a desktop PC. The complete life cycle of a runtime instance completes in less than 300 microseconds.
* Almost complete ES2020 support including modules, asynchronous generators and full Annex B support (legacy web compatibility).
* Passes nearly 100% of the ECMAScript Test Suite tests when selecting the ES2020 features. A summary is available at Test262 Report.
* Can compile Javascript sources to executables with no external dependency.