Open-source licenses and third-party software
Last updated:
This table describes the main frameworks, fonts and browser runtimes used by SkillAIVibe. npm versions are read from the installed dependency inventory at build time. Native components inside prebuilt runtimes have separate upstream notices and may have their own licenses.
Where a component ships as a pre-built binary served from this site, its available license and notice texts are placed alongside the binary. These texts preserve upstream attribution; their presence does not by itself verify every component's provenance or satisfy all source-distribution obligations.
The learning libraries, fonts and language runtimes below are self-hosted and served from this site's own domain. Google Analytics is the only listed integration that contacts an outside service at runtime, and it is not rendered until a visitor explicitly accepts optional analytics. The Privacy Policy explains that choice.
License texts and dependency inventory
The downloadable npm notices preserve license text for the installed dependency graph, including build and server packages that do not run in your browser. The versioned inventory records 267 installed packages and 130 additional license texts inside Next.js. This inventory covers npm packages; it is not a complete bill of materials for native code inside WebAssembly binaries.
Font license texts: Geist and Geist Mono. Runtime-specific LICENSE and NOTICE files remain with their downloads under /vendor/.
| Component | Version | License | What it is used for |
|---|---|---|---|
| Next.js | 16.3.5 | MIT License | The web framework this site is built with — it generates every page you read. |
| Next.js Third Parties | 16.3.5 | MIT License | Loads Google Analytics only after a visitor has explicitly accepted optional analytics. |
| React | 19.2.8 | MIT License | Powers the site's interactive parts, including the code editor, the output console and the progress page. |
| Tailwind CSS | 4.3.3 | MIT License | Utility CSS, compiled at build time into this site's own stylesheet. Nothing is loaded from a CDN. |
| react-markdown | 10.1.0 | MIT License | Renders the lessons, exercises and articles, which are written in Markdown. |
| CodeMirror 6 | 6.43.11 | MIT License | The code editor in every playground, exercise and practice problem, with its Python, JavaScript/TypeScript, Java, C and C++, SQL, HTML and CSS language modes. |
| Pyodide | 314.0.6 | Mozilla Public License 2.0 | The Python execution engine — real CPython compiled to WebAssembly, so Python on this site runs as actual Python. Copied from its npm package at build time and served from this site. |
| CPython standard library (inside Pyodide) | — | Python Software Foundation License | The Python standard library, available inside the sandboxed runtime so imports like math, collections and itertools work as they do in real Python. |
| TypeScript | 5.9.3 | Apache License 2.0 | The TypeScript compiler itself, served from this site to your browser so TypeScript is genuinely type-checked rather than having its types stripped. Copied from its npm package at build time. |
| teavm-javac | build pinned 2026-09-12 | Apache License 2.0 | The Java toolchain — the OpenJDK Java compiler combined with TeaVM and compiled to WebAssembly, so Java is genuinely compiled and run in your browser. Self-hosted and pinned by SHA-256. |
| OpenJDK javac (compiled into teavm-javac) | not independently verified | GNU GPL v2 with the Classpath Exception | The Java compiler inside the prebuilt toolchain. The source-provenance limitations are explained below and in its accompanying notice. |
| Emception | build pinned 2026-09-12 | MIT OR Apache-2.0 | The C and C++ toolchain: clang, lld and an Emscripten sysroot compiled to WebAssembly, so C and C++ are compiled and run in your browser. Loaded only when you start it; self-hosted and pinned by SHA-256. |
| LLVM / clang / lld (inside Emception) | Emscripten 3.1.24 build | Apache License 2.0 with LLVM Exceptions | The C++ compiler and linker themselves. |
| Emscripten (inside Emception) | 3.1.24 | MIT / University of Illinois NCSA | The system libraries and runtime glue that let a compiled C++ program run as WebAssembly. |
| sql.js | 1.14.2 | MIT License | The engine behind the SQL playground: SQLite compiled to WebAssembly. Its JavaScript is bundled into the sandbox, and its WebAssembly file is copied from its npm package and served from this site. |
| SQLite (inside sql.js) | 3.49.1 | Public domain | The database engine itself, which runs every SQL query in a fresh in-memory database that is discarded after the run. |
| ruby.wasm (@ruby/3.4-wasm-wasi) | 2.10.1 | MIT License | The Ruby execution engine — real CRuby compiled to WebAssembly via WASI, so Ruby on this site runs as actual Ruby. Copied from its npm package at build time. |
| CRuby (inside ruby.wasm) | 3.4.1 | Ruby License (2-clause BSDL, or GPLv2 at your choice) | The Ruby language interpreter itself. |
| php-wasm | 0.1.0 | Apache License 2.0 | The PHP execution engine — real PHP compiled to WebAssembly, so PHP on this site runs as actual PHP. Copied from its npm package at build time. |
| PHP (inside php-wasm) | 8.4 | The PHP License 3.01 | The PHP language interpreter itself. |
| webR | 0.6.0 | GNU GPL v3 (this binary distribution) | The R execution engine — real R compiled to WebAssembly, so R on this site runs as actual R. Copied from its npm package at build time; see the note below. |
| R (inside webR) | 4.6.0 | GNU GPL v2 / v3 | The R language interpreter itself, one of several GPL components webR's binary distribution bundles. |
| just-bash | 3.4.2 | Apache License 2.0 | A simulated bash shell, reimplemented in TypeScript rather than wrapping real bash — real syntax, variables, control flow and a wide slice of everyday coreutils, running entirely client-side with a small in-memory filesystem. Not a real system shell, and the Bash guide says so. |
| yaegi | commit fcb76d1e | Apache License 2.0 | A real Go interpreter, compiled to WebAssembly together with a small wrapper program of this site's own, so Go on this site runs as actual Go against its standard library. |
| Go (wasm_exec.js, inside the Go runtime) | 1.27.1 | BSD 3-Clause License | The WebAssembly host glue shipped with the Go SDK itself, needed to run a GOOS=js Go program inside a browser tab. |
| .NET WebAssembly runtime (Mono) & Roslyn | .NET runtime 10.0.12, Roslyn 4.14.0 | MIT License | The real C# compiler (Roslyn) and the Mono runtime that runs the compiled result, both compiled to WebAssembly, so C# on this site is genuinely compiled and run, not simulated. |
| Basic.Reference.Assemblies | Basic.Reference.Assemblies.Net90 1.8.3 | MIT License | The .NET reference assemblies Roslyn compiles a learner's C# against, since a browser has none of the usual ones on disk. |
| Geist and Geist Mono | via next/font | SIL Open Font License 1.1 | The site's typefaces for prose and for code. Self-hosted: the font files are served from this site, never from a third party's servers. |
A note on the Java compiler specifically
The prebuilt Java toolchain includes OpenJDK code licensed under GPLv2 with the Classpath Exception, plus separately licensed TeaVM components. The exception has specific conditions; it does not remove obligations attached to redistributing OpenJDK binaries. A license name and a general repository link alone do not establish complete corresponding-source coverage.
One thing this project cannot claim: these are prebuilt binaries, and the exact OpenJDK revision and the complete source/build inputs for the shipped artifact have not been independently verified. Published upstream recipes are evidence about a build, not a reproducibility result. This site has not independently rebuilt that artifact.
A note on R specifically
webR's licensing documentation classifies its compiled binary distribution under the GNU GPL Version 3. The R runtime is a large, separate WebAssembly download, fetched when a visitor uses the R playground. Its libraries, fonts and data include further licenses. The accompanying notices identify published upstream source and recipes; matching every shipped binary to complete corresponding source has not been independently verified.
A note on the C++ toolchain
The C++ toolchain is a prebuilt output of the Emception project. Its shipped payloads match a recorded upstream demo commit, but this site has not independently reproduced the complete build. It is pinned by SHA-256 so that the bytes we reviewed are the bytes you get. It is Emscripten 3.1.24 from late 2022, which the security page and the C++ playground both say plainly.
What this list is, and is not
This page documents major bundled software and an installed npm inventory. It does not certify universal license compliance or ownership of third-party components. It is separate from the question of what data the site sends or collects. SkillAIVibe keeps learning data in the browser and loads Google Analytics only after a visitor accepts it, as the Privacy Policy sets out. The words on this site, and the exercises, lessons and courses, are covered by the Copyright Policy.
If you notice this list is out of date with what the site actually ships, let us know.