OSSU
A free, self-paced computer science curriculum built from online university courses.ossu/computer-science
- Stars
- 211k
- Forks
- 26.1k
- Licence
- MIT
- Language
- HTML
- Last update
- 4 months ago
- Type
- Learning resource
What it is
OSSU (Open Source Society University) is a curated, ordered list of free online courses and books that together aim to cover a computer science degree. It is meant for people who want a well-rounded CS education on their own, with help from a community of other learners. The README says it is organized into Intro CS, Core CS, Advanced CS, and a final project.
- Follow the ordered Intro CS course to test whether computer science suits you
- Work through Core CS courses in order, covering programming, math, systems, theory, and security
- Pick one Advanced CS subject, such as advanced programming, and take its electives
- Estimate your finish date with the linked spreadsheet and track completions
- Build a final project to show what you learned
Great for
- Self-motivated adults who want a structured path through CS fundamentals
- People already educated in another field who want CS knowledge without a degree
- Learners who can commit roughly 20 hours a week over about two years, per the README's estimate
- People who want an ordered list of courses instead of choosing their own
- Students who value a community of peers through Discord and GitHub issues
Not ideal for
- People who need a recognized degree or credential, since the README says it is not merely for career training and does not describe any accreditation
- Learners who want a guided course with instructors and deadlines, since the path is self-directed
- Anyone with no time for a multi-year commitment, as the README suggests about two years at about 20 hours a week
- Beginners without high school math, since Core CS assumes algebra, geometry, and pre-calculus
How to get it
- 1
Read it online
Clone the repository
git clone https://github.com/ossu/computer-science - 2
Run it
- Open the OSSU CS website at https://cs.ossu.dev to see the current curriculum
- Check the prerequisites section and confirm you have high school algebra, geometry, and pre-calculus for Core CS
- Start with Intro CS: Introduction to Computer Science and Programming using Python
- Join the OSSU Discord to introduce yourself and find study partners
- Track your progress in a copy of the linked timeline spreadsheet
- 3
Get the most out of it
- Use the Discord server as your first stop for questions and study groups
- Take math courses in parallel with introductory courses, as the README suggests is popular
- Read CONTRIBUTING.md and HELP.md if you want to report course problems or get FAQ answers
- Check extras/courses and extras/readings for additional high-quality material outside the core path
- Use the spreadsheet with your start date and weekly hours to estimate your end date
Downloads
Strengths
- Free or nearly free: the README says all or nearly all course material is free, though some courses may charge for graded work
- Courses are drawn from well-known universities and are chosen against stated criteria such as being open for enrollment and matching CS 2013 guidelines
- Clear ordering, prerequisites, and time estimates for each course
Trade-offs
- Individual courses may charge for graded assignments, tests, or projects, so the total cost can vary
- The README warns that the spreadsheet and some third-party materials may be out of date, so the official site or repo should be checked
- No instructors or credentials are described in the README; progress depends on your own discipline
How it compares
| Project | Stars | Type | Level | Updated | Best for |
|---|---|---|---|---|---|
| computer-science (this) | 211k | Learning resource | advanced | 4 months ago | Self-motivated adults who want a structured path through CS fundamentals |
| javascript-algorithms | 197k | Learning resource | beginner | 3 months ago | Students learning core computer science concepts in JavaScript |
| Web-Dev-For-Beginners | 97.1k | Learning resource | beginner | 5 days ago | Complete beginners who want a structured, self-paced path into web development |
| open-source-cs | 23.8k | Learning resource | intermediate | 1.4 years ago | Self-taught learners who want a structured order of study |
| ciencia-da-computacao | 21k | Learning resource | beginner | 6 months ago | Brazilian Portuguese speakers who want a structured self-study computer science curriculum |
| tech-interview-for-developer | 17.7k | Learning resource | beginner | 1.4 years ago | Korean-speaking junior developers preparing for technical interviews |
Stats synced from GitHub. The assessment above was drafted with AI from the project's README on 2026-10-29 and may miss recent changes — check the README before relying on a command. MIT licence: free to use, modify and distribute, including commercially, as long as you keep the copyright notice.