WebAssembly Beyond the Browser

WebAssembly (Wasm) started as a way to run native code in browsers. Now it's becoming something much bigger.

WASI: WebAssembly System Interface

WASI provides a standard way for WebAssembly modules to interact with the operating system:

File system access

Network sockets

Environment variables

Clocks and random numbers

This makes Wasm portable across any system that implements WASI—not just browsers.

Universal Binaries

Write once, run anywhere. A WASI module runs the same on Linux, Windows, macOS, and in the browser.

Sandboxing

Wasm modules run in a capability-based security sandbox. They can only access what they're explicitly given.

Edge Computing

Cloudflare Workers, Fastly Compute, and others use Wasm for edge functions. Cold starts in milliseconds, not seconds.

Plugin Systems

Extend applications safely. Users can run untrusted code without risking the host system.

**Wasmtime**: Bytecode Alliance's reference runtime

**WasmEdge**: CNCF project, Kubernetes-native

**Wasmer**: Commercial runtime with great tooling

**wazero**: Zero-dependency Go runtime

Most languages compile to Wasm now:

Rust: First-class support

C/C++: Via Emscripten or wasi-sdk

Go: TinyGo or standard compiler

Python: Pyodide

.NET: Blazor WebAssembly

The future of compute might be Wasm modules running everywhere, from browsers to blockchains to satellites.