I thought I'll share interesting websites and projects I find along my way with you.

This one is the first:

https://github.com/evilsocket/opensnitch/

#OpenSnitch is a GNU/Linux port of the #LittleSnitch application firewall.

It will show a dialog once a new connection is made. The user can decide whether it should be allowed or declined. As well as how long the decision should last. The decision can be defined based on IP, Port, Executable, etc.