Reddit is a network of communities where people can dive into their interests, hobbies and passions. There's a community for whatever you're interested in on Reddit.

Stack Overflow is the largest, most trusted online community for developers to learn, share​ ​their programming ​knowledge, and build their careers.

Quora is a place to gain and share knowledge. It's a platform to ask questions and connect with people who contribute unique insights and quality answers. This empowers people to learn from each other and to better understand the world.