From SixXS Wiki
This is a review of protocol-translation tools that can be used to help transition to an IPv6 network.
- NT6Tunnel: this can be used with Pidgin and other programs to provide Windows IPv4 applications with a local tunnel to IPv6 servers. Example command: nt6tunnel.exe 5222 chat.
- Stone: a Japanese creation to allow programs to work with firewalls; also happens to translate IPv4 to IPv6. Example command: stone.exe localhost:5900 5900/v6
- XYNTService isn't a networking program: but it can be used run the other programs in a background process. You can add multiple program entries and start or stop them all as one NT-based service.
- PortProxy allows to remap any TCP IPv4 service to the IPv6 port (and vice versa) in Microsoft Windows, using the built-in netsh command.