Core platform
The lesson engine, reader, sandboxes, review system, and dictionary are all AGPLv3. Use it, fork it, self-host it, modify it. If you run a modified version as a service, the AGPL asks you to share your changes.
Open Source
Built in the open. Free forever. By design.
DURA's entire source — platform, content, and APIs — lives on GitHub under licenses chosen so the core can never be taken away.
APIs and integrations
The public API (dictionary, phases, verification) and integration libraries are Apache 2.0. Build on them without friction, commercial or otherwise.
Why AGPL, not MIT
MIT is a wonderful license for libraries. It's the wrong license for a learning platform whose value proposition is staying free forever.
Under AGPL, anyone can take DURA, make it better, and run their own version — but they have to share what they change. Nobody gets to fork it, put it behind a paywall, and pull up the ladder.
That's the point. The license is the promise.
How to contribute
DURA welcomes contributions of every size — from a typo fix to a whole new dictionary term.
- Content: add or improve a lesson, dictionary term, or assessment question. Every MDX file lives under
src/content/and follows a documented frontmatter schema. - Code: pick up a
good-first-issuelabel on GitHub. The repo runs ESLint, TypeScript strict, and a pre-commit hook so CI catches mistakes before you do. - Translations: DURA is English-first. If you want to lead a localization effort (Spanish, Portuguese, Japanese, or your language), open an issue.
- Reviews and bug reports: read a lesson, spot something wrong, open an issue. That's a contribution.
Architecture at a glance
- Next.js 15 App Router, React Server Components, static generation for lessons and dictionary terms
- TypeScript strict throughout, zero
any - Tailwind v4 with CSS variable tokens for theming
- IndexedDB via idb — every byte of user progress lives locally; nothing sent to any server
- FSRS-5 spaced repetition, implemented from scratch (no external dep)
- Sandpack for in-browser code execution, lazy-loaded so the initial bundle stays small
- Zustand for cross-component state, no Redux/MobX
- Privacy-first analytics — events queued to IndexedDB, no cookies, no third parties
Where we are on the roadmap
- Infrastructure · routes, IDB, API, theme · shipped
- Lesson pipeline · MDX, reader, interactive components · shipped
- Review, sandbox, dictionary · shipped
- Assessments, mastery gates, certificates · shipped
- Goals, gamification, study modes · shipped
- Marketing pages, TipButton · in progress
- Teacher dashboard and export engine · next
- Content sprint — all 406 lessons and 500 dictionary terms · after
- Polish, PWA, accessibility audit, launch · last
Contributors
DURA is new. The contributors wall is waiting for its first entry. Yours could be it.
Dustin Snellings · founderYour name here