> some sort of UI thing based on WASM might be the way to go
Oh dear hypothetical deity, please no!
I can best respond by copying my own response from another place:
Do you know Greenspun’s tenth rule?
https://en.wikipedia.org/wiki/Greenspun%27s_tenth_rule
It was about Lisp, so it’s an ancient thing now, but it still has truth.
As far as the Unix/Linux/xBSD world goes, it can be generalised like this:
Level 1: Any sufficiently complicated [container or VM management system] contains an ad-hoc, informally-specified, bug-ridden, slow implementation of half of Plan 9.
Level 2: Any sufficiently complicated [bytecode VM or runtime environment] contains an ad-hoc, informally-specified, bug-ridden, slow implementation of half of Inferno.
Wasm to me still smells very much like a second-hand, poorly-conceived, half-assed version of Dis.
> There is room for programs that do not need to be installed.
Sure there is room. But is this a desirable thing? Is it worth the price in inefficiency and insecurity?
If it is, and I am not 100% convinced of that, then design it right into the OS from the outset. Any effort to bolt it on later will be fatally flawed.