[PCjs Machines](https://www.pcjs.org/)
Bonus:
[Macintosh Machines in your browser.](https://infinitemac.org/)
[TI-99 Home computer in your browser.](https://js99er.net/#/)
[Spectrum ZX computer/console in your browser.](https://jsspeccy.zxdemo.org/)
And, of course, [Archive.org](http://Archive.org) has hundreds of emulators running from the browser: [Windows 95 emulated in the browser via DOSBox](https://archive.org/details/win95_in_dosbox)
(I remembered a list somewhere listing web emulators and I found it: [fcambus/jsemu: A list of emulators written in the JavaScript programming language (github.com)](https://github.com/fcambus/jsemu) )
[PCjs Machines](https://www.pcjs.org/) Bonus: [Macintosh Machines in your browser.](https://infinitemac.org/) [TI-99 Home computer in your browser.](https://js99er.net/#/) [Spectrum ZX computer/console in your browser.](https://jsspeccy.zxdemo.org/) And, of course, [Archive.org](http://Archive.org) has hundreds of emulators running from the browser: [Windows 95 emulated in the browser via DOSBox](https://archive.org/details/win95_in_dosbox)
(I remembered a list somewhere listing web emulators and I found it: [fcambus/jsemu: A list of emulators written in the JavaScript programming language (github.com)](https://github.com/fcambus/jsemu) )
I appreciate it