Web Assembly Study Notes

Building a Simple Wasm App

A hands-on walkthrough of building, compiling, and running a small WebAssembly module in both the browser and a standalone WASI runtime.

Comparing Wasm Runtimes

A practical comparison of Wasmtime, WasmEdge, wasmer, and browser engines, covering performance, WASI support, and ideal use cases for each.

Compiling C/C++ to Wasm with Emscripten

Learn how the Emscripten toolchain turns C and C++ source code into WebAssembly modules that run in browsers and Node.js.

Compiling to WebAssembly

How real-world languages like C/C++, Rust, and others compile down to WebAssembly using toolchains such as Emscripten and wasm-pack.

Debugging WebAssembly

Techniques and tooling for stepping through, inspecting, and diagnosing WebAssembly binaries, from DWARF source maps in the browser to disassembly with standal…

Loading and Instantiating a Wasm Module

How to fetch, compile, and instantiate WebAssembly binaries in JavaScript hosts, from raw ArrayBuffers to streaming compilation.

Memory Management in Wasm

How WebAssembly's linear memory model works, how it grows, and how it differs from garbage-collected host environments like JavaScript.

Passing Data Between JS and Wasm

Practical techniques for moving numbers, strings, and structured data across the JavaScript/WebAssembly boundary via linear memory.

Rust and WebAssembly

How Rust's toolchain and ownership model make it a natural fit for compiling safe, high-performance code to WebAssembly.

The Component Model Explained

How the WebAssembly Component Model lets modules written in different languages compose safely through typed interfaces instead of hand-rolled glue code.

The Wasm Binary Format

A tour of the actual bytes inside a .wasm file: the module header, sections, and how instructions are encoded.

The Wasm Execution Model

How WebAssembly actually executes: its stack machine, linear memory, module/instance/store relationship, and structured control flow.

The WebAssembly JavaScript API

A tour of the WebAssembly global object's core classes — Module, Instance, Memory, Table, and Global — and how JavaScript orchestrates Wasm.

WASI Explained

What the WebAssembly System Interface is, why it exists, and how it lets Wasm modules run safely outside the browser.

wasm-bindgen Explained

How wasm-bindgen generates the glue code that lets Rust and JavaScript exchange complex types across the Wasm boundary.

Wasm for Performance-Critical Code

How to identify, compile, and integrate performance-critical code paths as WebAssembly modules for near-native execution speed.

Wasm for Plugins and Sandboxing

Using WebAssembly's memory-isolated, capability-based execution model to run untrusted third-party plugin code safely inside a host application.

Wasm in Game Development

How game engines compile C++/Rust codebases to WebAssembly to ship performant games that run directly in a browser tab.

Wasm in the Browser

How browsers load, validate, compile, and execute WebAssembly modules alongside JavaScript, and how the two communicate.

Wasm Module Size Optimization

Practical techniques for shrinking WebAssembly binaries, from compiler flags and Binaryen's wasm-opt to trimming runtime and standard library overhead.

Wasm Outside the Browser

Running WebAssembly as a portable, sandboxed server and CLI runtime using WASI and standalone engines like Wasmtime and Wasmer.

Wasm Security Model

How WebAssembly's linear-memory sandboxing, structured control flow, and capability-based WASI design together minimize the attack surface of untrusted code.

Wasm Tables and Functions

How WebAssembly represents functions as first-class values, why linear memory can't hold them, and how Table enables indirect calls and function pointers.

Wasm Threads and SIMD

How WebAssembly's threads proposal (shared memory and atomics) and fixed-width SIMD unlock parallel and data-level performance for compute-heavy workloads.