various programing challenges
https://projecteuler.net - mostly mathematical, some tasks easy, but many need deeper analysis (at least wikipedia page).
http://coderbyte.com - various quality, duplicates
http://geocaching.com/ - geocaching site, various ciphers and puzzleds which can be solved by computer program
##Lists http://codecondo.com/coding-challenges/
##Notable tasks
- projecteuler.net/0096-Su_Doku
##Links https://en.wikibooks.org/wiki/X86_Disassembly/Disassemblers_and_Decompilers https://forums.gentoo.org/viewtopic-p-7177606.html