PeerGuardian PeerGuardian is a privacy oriented firewall application. It blocks connections to and from hosts specified in huge blocklists (thousands or millions of IP ranges). Its... Discontinued but still available, and still an alternative. Guest • Aug 2015 • 1 agrees and 1 disagrees Disagree Agree Free Open Source Mac Windows Linux Anonymity Peer-To-Peer Privacy Protection Add a feature 29 Like Discontinued Linux version seems to be still developed: last version, 2.3.1, was released in November 2015. Windows and Mac version are no longer developed and outdated: useless for Mac due to the evolution from IPW to PF internal firewall structure from 10.10 Yosemite on; for Windows PeerBlock, a continuation of PeerGuardian's development, is recommended by the developer.