Tech Inc CTF Challenge Website Scoreboard
For 'In Progress' listings, please put the highest level of the challenge that you have already completed!
There's also a global challenge scoreboard, that might be fun to use: https://www.wechall.net
This is a good set of Linux challenges - it starts super-easy, and gets harder.. there's 24 levels in total!
Finished: Brainsmoke, Melanie, Narya, Philip, Cool_Fire
30 levels atm (24 December 2013)
This is popular w/ the Dutch community, and it features web hacking (start w/ Essential Security) and other stuff..
This is all about embedded low-level hacking (aka hacking the doorbot). It features an MSP430 with a debugger, your task is to exploit the lock so you can gain entry to new locations.