[codermike]

I hadn't heard of Toit. That's very interesting.

Moddable's XS engine is great, and covers the full ECMAScript spec. I did a bit of contract work on the XS engine a while back, and I participated for some time as an invited expert on the ECMA TC53 committee for JS on embedded systems alongside Moddable and can say that I have a lot of respect for what they've done. For people who are running large enough devices to support XS, I highly recommend it.

I created Microvium in part because over my career as a firmware engineer there was a common pattern that most of the devices I worked on were just way too small to run any of the off-the-shelf JS engines. Even on larger microcontrollers, it's a big commitment for a company to allocate 50kB+ of ROM and 1kB+ of RAM just to run JavaScript, especially since the firmware teams were dominated by C programmers who consider JS to be very low on the priority list.