PeerBlock is a new version (aka a "fork") of the popular Peer Guardian 2 software. It blocks "known bad" computers from accessing yours, for example governments, corporate entities, and those flagged for anti-p2p activities. Peer Block maintains the functionality of the original Peer Guardian 2 program, but includes fixes for various issues that remain unaddressed in the latest (~2 year old) version of PG2.
PeerBlock supports Windows 2000, XP, Vista, and Win7 in both 32- and 64-bit flavors.
Many thanks to the original developers of Peer Guardian! You've created a great piece of software, one that served us all well for many years. Hopefully at some point we'll be able to merge the changes coming to Peer Block back into PG2/PG3, but for now I'll be happy just with a piece of software that works well on my new Windows 7 64-bit machine.