zen80 is a simple Z80 emulator written in Go.
https://github.com/ha1tch/zen80
It's a preview version and it still doesn't pass all the tests, but it's starting to show some promise.
This is not a ZX Spectrum emulator, this is Z80 only (although some source examples show how to use zen80 to implement a running system).
The older hardcoded Spectrum emulator that has optimised screen display will be frankensteined with open heart surgery once I have the new zen80 ready and passing all the tests.