Hackr.io is an awesome online search engine specially created for computer geeks and programming enthusiasts. It permits the users to easily find coding courses and tutorials for a big number of programming languages.
The front page lists some of the programming languages and topics that it supports. I will insert below a bunch of screenshots to show you the big list of topics on the first page.
If you click on one of the topics, you will get a list of all the courses and tutorials maching the topics, sorted by user votes. When a topic is clicked, you get a list of online sources you could use to learn things you are interested of.
The tutorials and guides can be added by everyone who creates a user. This is a community-driven project, updated and maintainted by the community.
For now, the number of tutorials is rather low, despite the fact that there are a lot of categories. Another drawback is the fact that the search engine does not work as it should. It justs finds the category from the first page.
Once the two things are addressed, this would become a rather convenient learning platform, bringing together tutorials from different sources.