Like any other map, The Internet map is a scheme displaying objects’ relative position; but unlike real maps (e.g. the map of the Earth) or virtual maps (e.g. the map of Mordor), the objects shown on it are not aligned on a surface. Mathematically speaking, The Internet map is a bi-dimensional presentation of links between websites on the Internet. Every site is a circle on the map, and its size is determined by website traffic, the larger the amount of traffic, the bigger the circle. Users’ switching between websites forms links, and the stronger the link, the closer the websites tend to arrange themselves to each other.

CodeHS is a coding education platform with an LMS, various curricula and IDE sandboxes, and more.  There's a free version, or you can pay for more features (like a built-in gradebook).

An online interactive resource for high school students learning about computer science.

CS Unplugged is a collection of free teaching material that teaches Computer Science through engaging games and puzzles that use cards, string, crayons and lots of running around.

When we started Codecademy, our goal was to give anyone in the world the ability to learn the skills they’d need to succeed in the 21st century. We set out to create a new, interactive way of learning — making it engaging, flexible, and accessible for as many people as possible. Since then, we have helped millions of people worldwide unlock modern technical skills and reach their full potential through code.

We want to create a world where anyone can build something meaningful with technology, and everyone has the learning tools, resources, and opportunities to do so. Code contains a world of possibilities — all that’s required is the curiosity and drive to learn. At Codecademy, we are committed to empowering all people, regardless of where they are in their coding journeys, to continue to learn, grow, and make an impact on the world around them.