IP Monitor notifies you when your public IP address changes
IP Monitor is a simple application which monitors your public IP address for changes and lets you set different kinds of notifications such as email, audio, pop up or executing a command. It can also run in background as a Windows service or Linux/Mac daemon.
The Internet Protocol Address Calculator is an open-source java-based tool. This calculator will assist network administrators to perform calculations over both IPv4 and IPv6 address space. A handy whois search client is also integrated into this tool.
RevolvingProxy is a cross platform HTTP Proxy application that is designed to be installed on a server that has been assigned multiple IP addresses. Each connecting client is assigned a different IP address for security testing or other purposes.