WebAssembly by Example is a hands-on introduction to WebAssembly using annotated example projects. Get started with the fibonacci example or click on any of the links below. You are encouraged to copy-paste bits from these examples into your own projects as needed.

WebAssembly is a type of code that can be run in modern web browsers — it is a low-level assembly-like language with a compact binary format that runs with near-native performance and provides languages such as C/C++, C# and Rust with a compilation target so that they can run on the web. It is also designed to run alongside JavaScript, allowing both to work together.

🚩 Basics

• Return 42 in WebAssembly Text Format via JavaScript
• Fibonacci sequence in C via JavaScript
• Fibonacci sequence in Rust via JavaScript
• "Hello world!" in C via JavaScript
• Fibonacci sequence in C via Python with $X
• Fibonacci sequence in C via Rust with $X
• Fibonacci sequence in C via Java with $X
• Fibonacci sequence in Rust via C with $X
• Fibonacci sequence in Rust via C++ with $X

👨‍💻 WASI

The WebAssembly System Interface (WASI) is a set of APIs for WASI being developed for eventual standardization by the WASI Subgroup, which is a subgroup of the WebAssembly Community Group.

• "Hello WASI!" in Rust via JavaScript using @wasmer/sdk
• Compile C++ to WASI preview1

🧰 Specialized tooling

• Use Rust in JavaScript through wasm-pack
• Use AssemblyScript in JavaScript
• Use C++ in JavaScript through Emscripten
• Use Go in JavaScript through GOOS=js
• Write Rust web apps using trunk

📦 WebAssembly component model

The WebAssembly Component Model is a broad-reaching architecture for building interoperable Wasm libraries, applications, and environments.

• Create a WebAssembly component from Rust using cargo-component
• Create a WebAssembly component from JavaScript using jco
• Compose WebAssembly components using wasm-tools
• Use a WebAssembly component in JavaScript through jco
• Use a WebAssembly component in Python with wasmtime
• Use a WebAssembly component in Rust with wasmtime

⚙️ Advanced

• Compile Rust to WASIX
• Run WASIX in JavaScript with Wasmer
• Compile Rust to 64-bit WebAssembly
• Use SDL2 in C++ in JavaScript through Emscripten
• Run WASI preview1 on Arduino with Wasm3
• Write an HTTP endpoint in Rust with Wasmer

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