Granted, yeah, we never (or haven't yet) really transitioned to running "full legacy software" inside the browser, or at least it's not common place. That said, I've seen people compile Wine to wasm, Linux to wasm, and lots of other things to wasm, and run em in a browser. Many of the "fake" demos could be done for real now.
The one aspect that remains thoroughly farcical is an equivalent of Wine for OS X/Cocoa good enough to run a web browser. :-(
[edit] And asm.js kind of died on the vine. Not sure how to feel about that one. Wasm could he described as an evolution of the same idea, but in a lot of ways it's something entirely different.
Probably wouldn’t be too hard to boot Linux (under QEMU compiled for wasm), and then fire up a Windows 95 VM using QEMU TCG …
Could repeat this a few times - Inception style…
I wonder if air quality/humidity permit actually seeing this far though… That’s a lot more “air” than looking up toward space…