Yes, this does seem to offer a similar functionality to ZoneAlarm.
What worries me is that it is not available in the Ubuntu software repositories. Until now I've found absolutely everything there. Weird. I do not want to install experimental or unsupported/abandoned stuff that might force me to debug or reinstall my system at the next kernel upgrade or whatever.
I'm very interested in opinions of actual daily users
Does it work without problems? What Linux distribution do you use it with?