I have updated the public ZERO node with IP 94.176.235.178 that accepts incoming connections. It is now based on the latest ZERO code-base at
https://github.com/zerocurrency/zero - updated by the original Zero developer.
Everyone interested may add it to their config. file ~/.zero/zero.conf:
addnode=94.176.235.178
Thanks, zerodev2. Your node is now in github installation steps too.