SixConf Network Configuration Tool for Windows

SixConf is a powerful tool for learning or teaching IPv6. It is not Open Source, but it is free app for Windows. See the User Guide for full details, but here is a screenshot of the main window to give you an idea of how it works. You can view all IPv6 and IPv4 addresses, including unicast, multicast, etc. You can add new addresses. It supports all network interfaces on your PC.

SixConf v2.0.2 User Guide

SixConf v2.0.2 Installer (download and rename to .exe)