The program being used is https://justine.storage.googleapis.com/emulator.com with the -t flag passed for the tui gui. Please note that I've only tested it on Linux and it's only intended for static executables, not shared objects.

I'm not sure exactly what debugger is used, but gdb dashboard can be set up in a similar way. It's just stepping through instructions and viewing the registers and some memory regions.

https://github.com/cyrus-and/gdb-dashboard

Though any debugger should be able to give the same information (including just plain gdb).