RC2014

WizNet v1 Ethernet
https://groups.google.com/forum/#!msg/rc2014-z80/T7j-9CAsKAo/pLuXJ34mBwAJ

https://github.com/markt4311/MT011
https://github.com/jayacotton/inettools-z80

CP/NET
https://github.com/durgadas311/cpnet-z80

CP/M with built in driver support for specific Ethernet adapters including WizNet.