I learned about Xss mitigation 3-4 years ago through google gruyere, a tutorial that came with a sandboxed environment to practice in [1] Where did others lear

I learned about Xss mitigation 3-4 years ago through google gruyere, a tutorial that came with a sandboxed environment to practice in [1] Where did others learn about XSS mitigation? Any resources to recommend? [1] https://google-gruyere.appspot.com/ https://google-gruyere.appspot.com/