There are 2 repositories under ipv4-support topic.
Arcus, developed by Sandia National Laboratories, is a C# library for calculating, parsing, formatting, converting and comparing both IPv4 and IPv6 addresses and subnets. It accounts for 128-bit numbers on 32-bit platforms.
Intra-session Network Coding Transport Protocol for IPv4 and IPv6
Simple easy-to-use C library for manipulating TCP/UDP networks in IPv4/IPv6.
A desktop application to use on Microsoft Windows systems. It count IP addresses by knowing broadcast address and host IP address.
A Python Webserver that would locally host a website you're working on your computer, or even on your local network. So that you don't need to enter the path of the HTML document onto your web browser.