Embedded Security CTFhttps://microcorruption.com
EnigmaGrouphttp://www.enigmagroup.org/
Escapehttp://escape.alf.nu/
Google Gruyerehttp://google-gruyere.appspot.com/
Gh0st Labhttp://www.gh0st.net/
Hack This Sitehttp://www.hackthissite.org/
HackThishttp://www.hackthis.co.uk/
HackQuesthttp://www.hackquest.com/
Hack.mehttps://hack.me
Hacking-Labhttps://www.hacking-lab.com
Hacker Challengehttp://www.dareyourmind.net/
Hacker Testhttp://www.hackertest.net/
hACME Gamehttp://www.hacmegame.org/
Halls Of Valhallahttp://halls-of-valhalla.org/beta/challenges
Hax.Torhttp://hax.tor.hu/
OverTheWirehttp://www.overthewire.org/wargames/
PentestIThttp://www.pentestit.ru/en/
CSC Play on Demandhttps://pod.cybersecuritychallenge.org.uk/
pwn0https://pwn0.com/home.php
RootContesthttp://rootcontest.com/
Root Mehttp://www.root-me.org/?lang=en
Security Treasure Hunthttp://www.securitytreasurehunt.com/
Smash The Stackhttp://www.smashthestack.org/
SQLZoohttp://sqlzoo.net/hack/
TheBlackSheep and Erikhttp://www.bright-shadows.net/
ThisIsLegalhttp://thisislegal.com/
Try2Hackhttp://www.try2hack.nl/
WabLabhttp://www.wablab.com/hackme
XSS: Can You XSS This?http://canyouxssthis.com/HTMLSanitizer/
XSS Gamehttps://xss-game.appspot.com/
XSS: ProgPHPhttp://xss.progphp.com/