The need for IP blockers arises from the fact that users of peer-to-peer networking often have their privacy violated.
Its origin seeds in targeting aggressive IPs while you use P2P. Not only is its source code open for you to read, use, and modify - but the project is open for you to join and contribute in any form (code, documentation, bug reports, web and support).
Peer Guardian Linux: ------------------- Actively developed. However the team is very small and with few spare time. See file releases and the code in the git repository. The last publicly released source (1.5.1) is available as file download here and in the git repository.
Peer Block maintains the functionality of the original Peer Guardian 2 program, but includes fixes for various issues that remain unaddressed in the latest (~3 year old) version of PG2. Make sure to read the "Known Issues" sticky to see if your problem's already known (and maybe resolved), and also for what we need from you if we're going to be able to help! You can also post and report any problems you're having with the forum software itself or if you have any ideas on how to improve it, or just generally post any discussions you have not specifically related to Peer Block Support.
Please note this does not mean you are allowed to spam the forums.
But there are reports that these don't work, see https://sourceforge.net/p/peerguardian/discussion/446996/thread/013e8113/?