wasmerio/wasmer

Wasmer is a runtime for WebAssembly, often shortened to Wasm. WebAssembly is a portable, sandboxed format that lets the same compiled program run on very different machines and operating systems without modification. Wasmer takes those .wasm programs and executes them, the README says, at near-native speed and inside a sandbox so they can't read your files, touch the network, or read environment variables unless you explicitly allow it. The README frames Wasmer as a way to ship lightweight, container-like workloads that run anywhere, desktop, the cloud, edge servers, or inside a browser. Out of the box it supports WASI and WASIX, two standardized interfaces that let a WebAssembly program do useful real-world things like read files or open sockets when permitted. There is a package registry at wasmer.io where you can pull pre-built programs (the README's first example is a classic cowsay) or publish your own. The Wasmer Edge product builds on the same runtime to deploy and host websites and services. You install Wasmer with a one-line shell script, or through a long list of package managers including Homebrew, Scoop, Chocolatey, PowerShell, and cargo install. Beyond the standalone command-line runner, the Wasmer SDK lets you embed the runtime inside an application written in another language: Rust, C, C++, C#, D, Zig, Python, JavaScript, Go, PHP, Ruby, Java, R, Postgres, Swift, Dart, Crystal, Lisp, Julia, V, and OCaml integrations are all listed. You would reach for Wasmer when you want to run untrusted or portable code safely, add a plugin system to an app, or deploy small workloads to edge locations without spinning up traditional containers. The project itself is written in Rust.