The free, text-first library of real-world developer and STEM knowledge.
- 367 guides, 1,575 phases, 27 categories - Git, operating systems, hardware, networking, databases, architecture, security, DevOps, infrastructure, performance, 7 full programming languages and 30+ frameworks end-to-end, plus Logic, Mathematics, and Physics for the reasoning underneath it all.
- Everything is laddered A→Z. Each category opens with "what this actually is" for someone who's never touched it, and ends at genuinely advanced material - no assumed knowledge, ever.
- It's not just reading. Interactive playgrounds (regex testers, sorting visualizers, a real in-browser terminal), inline quizzes, hands-on exercises, runnable Python/JS/SQL code blocks, and animated instrument-style explainers (a live CPU clock signal, a network latency trace, a git rebase played out step by step) for the concepts that are easier to watch than read.
- An AI tutor that answers questions about the exact phase you're reading, grounded in and citing the guide's own content - not a generic chatbot bolted on the side.
- Your own private highlights and notes on any phase, spaced-repetition review, a local skill map / roadmap of everything you've covered, and a set of logic/pattern brain games to keep the fundamentals sharp after you've read them once.
- Built to stick around, not just be read once. Offline-capable (installable PWA), exportable to EPUB, shareable "TIL" cards for what you just learned, and a public backlog where anyone can vote on what gets written next.
- Free. No account, no paywall, no ads. It stays that way.
A content-first split: the guides are the product, the platform serves them.
guides/ Markdown source of truth - every guide, every phase, every quiz/exercise
platform/
core/ Rust: ingest, SQLite storage, Tantivy full-text search
server/ Rust (axum): the public + admin API
web/ SvelteKit: SSR frontend, admin CMS, search UI
- Guides are plain Markdown with YAML frontmatter - no CMS lock-in, readable and diffable in a PR. Interactive elements (quizzes, exercises, playgrounds, animated explainers) are authored as fenced code blocks right in the Markdown.
- The server ingests
guides/on startup (and on a timer, and on demand from the admin panel) - drop a folder in, it goes live. No database migration to write a guide. - Search is real full-text search (Tantivy), not a fuzzy string match - typo-tolerant, ranked, same engine that powers the in-app AI tutor's "look this up in the guides" tool.
- Built to be read by machines too. Every guide phase is independently citable (its own URL, its
own JSON-LD
Article/FAQPagestructured data), served as clean semantic HTML, and available as raw Markdown to anything that asks for it (Accept: text/markdown) - including a small MCP server so AI agents can search and read the library directly. - Diagrams render server-side and follow your theme. Mermaid diagrams in guides are baked to
static SVG at ingest by a pure-Rust engine -
mermaid-to-svg, vendored from xAI's Grok Build (itself a patched fork of warpdotdev/mermaid-to-svg) - so the browser never loads mermaid.js. The engine bakes fixed colors, so to make one baked SVG follow every site theme (light, dark, sepia, nord, dracula, ...) live, each diagram is rendered once with sentinel colors thatapp.cssremaps to the theme's design tokens in the CSS cascade - no per-theme baking, no JavaScript, and it themes gitGraph/sequence/ER diagrams too. If you want theme-adaptive server-rendered Mermaid in your own Rust project, that sentinel + CSS-remap technique (seemermaid_ssr.rs) is yours to reuse. The vendored crates keep their own MIT / Apache-2.0 licenses (NOTICE).
Guides live in guides/<category>/<slug>/ as plain Markdown - no code required to write one.
Found something wrong in a guide, or a command that doesn't work anymore? Open an issue or a PR - small, factual corrections are exactly the kind of contribution this project wants most.
The whole repository - guide content and code alike - is licensed under CC BY-NC-SA 4.0: share it, adapt it, teach with it, even train models on it - just credit the source, don't sell it, and share alike.