freeCodeCamp.org's open source codebase and curriculum. Learn to code at home.
:books: Freely available programming books
Short CSS code snippets for all your development needs
Learning operating system development using Linux kernel and Raspberry Pi
💿 Free software that works great, and also happens to be open-source Python.
Organize world's knowledge, explore connections and curate learning paths
Source code for Hacker101.com - a free online web and mobile security class.