It all started with visual simulation of 6502 written in java script and simulation 6502 barely on few Hz, than later more chips were added ie 6800, arm and Z80.
Goran Devic was not happy with Zilog Z80 visual simulator so he used covid-19 time and hence Z80 Explorer was created.
Z80 Explorer is also Zilog Z80 netlist-level simulator capable of running Z80 machine code, but also ads few features that may understand or explain or reverse engineer z80 chip better, but also provides with few more tools like oscilloscope that may help you visualize signals.
Now netlist simulation moves to your computer and it is a bit faster from java script one that runs only on few Hz, on your computer you will get one to few kHz, but still 1500-4000 slower that z80 usually runs in retro computers.
There is also recorded video that shows what Z80 explorer can do.
We hope that some day we will see new version that will be capable to show anycpu explorer (that have available netlist)
Until that Z80 explorer have great user guide and Z80 Explorer source is available on github.
But wait there is more: Author pushed it even further with Z80Explorer.
What you would say to booting ZX Spectrum within Z80 Explorer netlist simulator.
That alone deserve to check blog of Goran Devic.