PeerGuardian

PeerGuardian is a privacy oriented firewall application. It blocks connections to and from hosts specified in huge blocklists (thousands or millions of IP ranges). Its origin seeds in targeting aggressive IPs while you use P2P.





PeerGuardian Windows:
Not developed anymore. It's highly recommended to use PeerBlock instead, which is a continuation of PeerGuardian's development in Windows, with bug fixes and support for Windows Vista and Windows 7.
New contributors and/or collaboration with peerblock.com  are welcome!