PeerGuardian

One of the coolest things about PeerGuardian 2 is that it’s Open Source. That means the code isn’t locked away anyone can check it out, tweak it, or even build something new from it. This openness invites collaboration, so bugs get spotted and fixed quickly, and you never have to worry about hidden backdoors or spyware sneaking into your system.

Originally developed by Phoenix Labs, PeerGuardian 2 was a powerful IP blocker for Windows. It came packed with handy features like support for multiple blocklists, easy list editing, automatic updates, and full IPv4 coverage blocking TCP, UDP, ICMP, and more. For anyone into peer to peer sharing, it was a go to tool for keeping your online activity private and secure.

Even though the original developers stopped working on it, the project didn’t just fade away. A new team picked up the torch and continued improving it under a new name: PeerBlock. So if you’re looking for a modern version with ongoing updates and support, that’s the way to go.