Thx a lot for the nice words pona-a. Here is my presentation of principia at the IWP9 workshop if you are interested: https://www.youtube.com/watch?v=blVTDhr4QN8

Projects like this are generational achievements, and we should demand public funding be given to them. It is a great loss its writer had to step down for 5 years, being too busy with an industry job, when they could have been so meaningfully advancing CS education.

Plan9 os used as teaching system thought book.

I heard Plan9 simple simpler than Unix.

And Go lang, created by Plan9 person, is simple too.

So basing Plan9 can be good.