I like this one, made by Google - it teaches XSS vulnerabilities: https://xss-game.appspot.com/ https://xss-game.appspot.com/ It's been discussed on HN twice:

I like this one, made by Google - it teaches XSS vulnerabilities: https://xss-game.appspot.com/ https://xss-game.appspot.com/ It's been discussed on HN twice: https://news.ycombinator.com/item?id=13021869 https://news.ycombinator.com/item?id=13021869 https://news.ycombinator.com/item?id=7815237 https://news.ycombinator.com/item?id=7815237