## Computing
* [Learn X in Y Minutes](https://learnxinyminutes.com/)
* [Coursera](https://www.coursera.org/)
* [CTFtime.org](https://ctftime.org/)
* [CTF Write Ups 2016](https://github.com/ctfs/write-ups-2016/) [2017](https://github.com/ctfs/write-ups-2017/) [2015](https://github.com/ctfs/write-ups-2015/) [2014](https://github.com/ctfs/write-ups-2014/) [2013](https://github.com/ctfs/write-ups-2013/)
* [Learn Python the Hard Way](https://learnpythonthehardway.org/book/)
* [Dive Into Python](http://www.diveintopython.net/)
* [DEF CON Media Server](https://media.defcon.org/)
* [CCC Media](https://media.ccc.de/)
* [Toorcon Videos](https://www.youtube.com/results?search_query=toorcon+2016)
## Math
* [OpenStax](https://openstax.org/subjects/math)
* [Khan Academy](https://www.khanacademy.org/)
* [Project Euler](https://projecteuler.net/)
* [Millennium Prizes](http://www.claymath.org/millennium-problems)
## Science
* [CrashCourse](https://www.youtube.com/user/crashcourse/playlists)
* [OpenStax](https://openstax.org/subjects/math)
* [Khan Academy](https://www.khanacademy.org/)
* [Nobel Laureates](https://www.nobelprize.org/nobel_prizes/lists/all/index.html)
## Literature
* [Project Gutenberg](http://www.gutenberg.org/)
* [Librivox](https://librivox.org/)
* [Nobel Laureates](https://www.nobelprize.org/nobel_prizes/literature/laureates/)
## Law
* [Supreme Court Arguments Audio](https://www.supremecourt.gov/oral_arguments/argument_audio.aspx)
* [PACER](https://www.pacer.gov/)
## Radio
* [SDR with HackRF](https://greatscottgadgets.com/sdr/)
* [No-Nonsense Study Guides](http://www.kb6nu.com/study-guides/)
## [Neg9 Leaderboard](https://neg9.org/leaderboard/)
* [OverTheWire](http://www.overthewire.org/)
* [Vortex](http://www.overthewire.org/wargames/vortex)
* [Semtex](http://www.overthewire.org/wargames/semtex)
* [Blacksun](http://www.overthewire.org/wargames/blacksun/)
* [Drifter](http://www.overthewire.org/wargames/drifter)
* [Krypton](http://www.overthewire.org/wargames/krypton)
* HES2010 (coming soon)
* Abraxas (coming soon)
* [Bandit](http://www.overthewire.org/wargames/bandit)
* [Leviathan](http://www.overthewire.org/wargames/leviathan)
* [Narnia](http://www.overthewire.org/wargames/narnia)
* [Behemoth](http://www.overthewire.org/wargames/behemoth)
* [Utumno](http://www.overthewire.org/wargames/utumno)
* [Maze](http://www.overthewire.org/wargames/maze)
* [Manpage](http://www.overthewire.org/wargames/manpage)
* [Natas](http://www.overthewire.org/wargames/natas/)
* [SmashTheStack](http://smashthestack.org/)
* IO
* Tux
* Apfel
* Logic
* Blowfish
* Blackbox
* Amateria
* [Bright Shadows](http://www.bright-shadows.net/)
* JavaScript
* Exploit
* Crypto
* CrackIt
* Stegano
* Flash
* Programming
* Java-Applet
* Logic
* Special
* Science
* Information Gathering
* /dev/null
* [exploit-exercises](http://exploit-exercises.com/)
* Nebula
* Protostar
* Fusion
* [HackThisSite](https://www.hackthissite.org)
* Basic
* Realistic
* Application
* Programming
* Extbasic
* Javascript
* Stego
* [Real Digital Forensic](http://real-forensic.com/)
* [MysteryTwister C3](http://www.mysterytwisterc3.org)
* [Level I](http://www.mysterytwisterc3.org/en/challenges/level-i)
* [Level II](http://www.mysterytwisterc3.org/en/challenges/level-ii)
* [Level III](http://www.mysterytwisterc3.org/en/challenges/level-iii)
* [Level X](http://www.mysterytwisterc3.org/en/challenges/level-x)
* [The Code Book's Cipher Challenge](http://simonsingh.net/cryptography/cipher-challenge/the-ciphertexts/)
* [Regex Crossword](http://regexcrossword.com/)
* Tutorial
* Beginner
* Intermediate
* Experienced
* Palindromeda
* Double Cross
* Cities
* Volapük
* Hamlet
* Hexagonal
* [Pwnable.kr](http://pwnable.kr)
* Toddler's Bottle
* Rookiss
* Grotesque
* Hacker's Secret
* [Embedded Security CTF](https://microcorruption.com/)
* [the cryptopals crypto challenges](http://cryptopals.com/)
* [Set 1: Basics](http://cryptopals.com/sets/1)
* [Set 2: Block crypto](http://cryptopals.com/sets/2)
* [Set 3: Block & stream crypto](http://cryptopals.com/sets/3)
* [Set 4: Stream crypto and randomness](http://cryptopals.com/sets/4)
* [Set 5: Diffie-Hellman and friends](http://cryptopals.com/sets/5)
* [Set 6: RSA and DSA](http://cryptopals.com/sets/6)
* [Set 7: Hashes](http://cryptopals.com/sets/7)
* [Set 8: Abstract Algebra](http://cryptopals.com/sets/8)
* [id0-rsa.pub](https://id0-rsa.pub/)