PeerGuardian
PeerGuardian - a privacy oriented firewall application
...Its origin seeds in targeting aggressive IPs while you use P2P.
PeerGuardian Linux:
Not developed actively anymore. Team might still be around. Some unreleased changes on git. Outdated technology.
Peerguardian OS X:
Not developed anymore. We've lost contact with the OS X developer.
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. ...