LuLu

LuLu 1.2

Free
MacOS firewall that aims to block unknown outgoing connections.
 
1.2.3 (See all)

LuLu is the free open-source macOS firewall that aims to block unknown outgoing connections unless explicitly approved by the user. LuLu is currently in alpha.
This means it is currently under active development and still contains known bugs. As such, installing it on any production systems is not recommended at this time.