Version 6 (or IPv6). IPv4, our current standard, is running out of IP addresses for electronic devices as it is using a 32-bit address scheme, allowing for "only" 2^32 addresses, or about 4 billion IP addresses.
IPv6 pretty much solving this by making the IP address a 128-bit hexadecimal, consisting of alphanumerical characters rather than just numbers, allowing for 3.4*10^38, or 340 undecillion IP addresses, which we have pretty much no chance of running out of IP addresses with current technology :p