Maths, science and economics from basics to advanced.
Structured lessons with practice and mastery tracking, from arithmetic through calculus, statistics and economics. The statistics track pairs well with the datasets in the Data section.
Thousands of hours of coding lessons and certifications.
Interactive course · BSD / open
The best introduction to computer science, free to audit.
Video course · Creative Commons
Real MIT course materials, openly published.
Course materials · Creative Commons
How valid tests are actually built and validated.
Open textbook · Creative Commons
Free courses, frequency lists and spaced repetition.
App + decks · AGPL / open source
Measurable typing improvement in minutes a day.
Web app · GPL / open source
Local models on your own machine, no API bill.
Desktop runtime + CLI · MIT / open source
Production-ready SPA skeleton with strict TS and fast HMR.
Git repository template · MIT / open source
Every utility class, searchable and offline-friendly.
Web reference · MIT / open source
