The new Peer Guardian Linux is the official successor and based on the Mo Block fork NFBlock, blockcontrol and mobloquer.
The usage is nearly identical, just type "pglcmd" instead of "blockcontrol". Note: Since version 0.9 RC1 Mo Block no longer conflicts with other firewalls.
It is capable of blocking incoming and outgoing connections based on IP blacklists.
The aim of its use was to block peers on the same torrent download from any visibility of your own peer connection using IP lists.
It's official successor is Peer Guardian Linux (pgl).
The system is also capable of blocking custom ranges, depending upon user preferences.
The Windows version of this program has been discontinued in favor of other applications (Phoenix Labs encourage current Peer Guardian users to migrate to Peer Block which is based on Peer Guardian 2 Development on Peer Guardian started in late 2002, led by programmer Tim Leonard.
Peer Guardian 2 integrates support for multiple lists, list editing, automatic updates, and blocking all of IPv4 (TCP, UDP, ICMP, etc), making it the safest and easiest way to protect your privacy on P2P.
Peer Guardian 2 is Open Source, meaning the program code is available online for anyone who wants it.