Online code editors

Question

Hello,

Lets say, I am building a website like CodePen.io and I need an online code editor implemented inside. What libraries would you suggest me using and how do I go about doing it?

Thanks,
CrAzYz_

Answer 1

Nvm. I've found my own answer. Those comments above were literally not what I needed

Answer 2

modernizr.js

Answer 3

w3schools.com or jsfiddle.net