There were several opensource tis-100 vm/interpreters made. Here is one I found, no idea if it is any good. https://github.com/melograph85/tis100

What I would always dream about was actual tis-100 like hardware, each module a small cheap microcontroller with 4 uarts(does that exist?) and a self interlocking module design so it is not constrained by a base chassis. And because I am insane, in-band programming, that is, each module needs to and can only be programmed by it's neighbors. It would be such a nightmare to actually make anything.

Heh, That would make for an interesting sequel. You thought tis-100 was obtuse and hard, now you have to design autonomous self duplicating code, it's the tis-400 virus processor.