NOPcon is a free non-profit hacker conference without any sales pitches. The second edition has released its call for papers and will take place June 6, 2013 in Istanbul, Turkey.
You can download it from the following link: https://packetstormsecurity.com/files/download/120844/nopcon2013-cfp.txt
Source: https://packetstormsecurity.com/files/120844/NOPcon-2013-Call-For-Papers.html