http://www.firewallleaktester.com/tests.htm 

So, after hearing about Kerio being discontinued I started poking
around and someone posted a like to this site. Has anyone used this
site? Some of this seems kinda sketchy to me, especially the testing
methods. I am probably going to go setup some VM machines sometime and
test out this software. I would really like to hear about people's
experiences about this site, if any.