I took the time and resurrected an old challenge site, originally hosted at quiz.ngsec.com.
If you are interested in old school challenging, you can try it out at ngsec.csokavar.hu
. I had much fun while working through these levels back in the days. Today it has a different flavour, since some of the levels became harder to solve in modern linux environments. It has low overall complexity, but I'm curious if some of you find it entertaining.