Open source... what do u think?

Hi guys! 

So today one of my favourite teachers told me that I will take part into a professional IT security training course for free.... WOW! :)

Also next saturday I'm going to go to the Open Source Day!! :)

This is the third year that I take part into this project and I love it! :)

By the way, tomorrow I may have a oral test in IT :)

But today I'm so happy!! :D

What do you think about Open Source OS?

For example BSD systems (OpenBSD, NetBSD, ...) or Linux systems (Ubuntu, Kubuntu, Mandriva, ...).
At the moment I'm using a Ubuntu system and a SlackWare OS.
I think they are amazing, also they are free! :D
Eheheh, and we know that free things are the best :P

keep following!