I was recently able to post my ZX81 emulator (started this year in March as a COVID stay-at-home project) on the web similar to JtyOne. It's only a ROM emulator called ZXSimulator, similar to Whitby's ZX Spectrum emulator for the Commodore 64 back in the late 80's but it works pretty well. It's implemented on a Sinclair QL (unexpanded, as that was the aim of the project -- i.e. see if I could get a ZX81 to run realtime without extra memory or acceleration) so by its nature has a pretty small audience. It was really just for the fun of doing it.
But getting it on the web gives a few more people reason to play with it. It's a ZX81 emulator running in a QL emulator (QLAY) running in DOS emulator (DOSBox) running in JavaScript on a browser. It runs faster than a stock ZX81/TS1000 on the web (on an unexpanded QL it's about 20% faster). It can't run machine code stuff, unfortunately, though eventually I aim to add some peek and poke functionality but not the full Z80 instruction set. I might upgrade it to a Whitby-like ZX Spectrum one eventually (depending on how long this pandemic lasts I suppose). On the plus side, you can touch type in BASIC programs as it doesn't use the keyword entry format.
In any case, you can find it here:
http://zxsimulator.epizy.com/
I hadn't planned on posting anything about it here since this forum is for Spectrum stuff and there is a similar forum for ZX80/81 stuff. But I saw this small section and your post so I thought, why not. In fact, this forum looks so similar to the ZX80/81 forum that, as I stumbled on this via Google and tried to post and it wouldn't let me, I was so confused I tried to unsuccessfully log on a couple of times until I realized this was a different forum :-/ I had found a thread about a vinyl game converted to a wave file for a ZX81 created in the 80's and wanted to see if it would run on my emulator.
