UltraVNC

to complex implement Counting char occurances within a string, counting string occurances within a string... I don't see the complexity here and could easily write that myself within 1 minute using PHP, or 5 minutes using Pascal, or 10 seconds using regular expressions. Just focus on square ...

Furthermore I'm not even sure how uVNC will work if Bob has only one IPv4 address and Alice has only one IPv6 address - from plain knowledge I'd say this is impossible, unless I'm missing a protocol specification. However, with i.e. British ISPs only serving IPv6 addresses and i.e. German ISPs only ...

If you enter an ipv6 ip No, IPv6 addresses are only recognized when being in the full format with padding zeroes:
affe:dead:cafe:fade:beef:0000:0000:0001 = the only one that works
affe:dead:cafe:fade:beef:0:0:1 = valid format without padding zeroes, uVNC doesn't recognize
affe:dead:cafe:fade ...