Wasmer WebAssembly Runtime

Wasmer is a free and open-source WebAssembly runtime that enables running WebAssembly (Wasm) modules outside the browser with near-native performance. Created by Syrus Akbary (founder and CEO of Wasmer Inc., a San Francisco-based company that raised $6.5 million in seed funding led by Bloomberg Beta in 2021) in 2019, Wasmer is designed to be the universal runtime for WebAssembly, enabling server-side, edge, and embedded execution of Wasm binaries. Key features: performance: Wasmer uses three compiler backends: Cranelift (fast compilation, default), LLVM (optimized execution), and Singlepass (balanced). Wasm modules execute at near-native speed. Language support: Wasmer provides SDKs for Python, Go, Ruby, PHP, JavaScript/Node.js, Rust, C/C++, Java, R, Zig, and Swift, allowing host applications in any language to call Wasm functions. WASI support: full implementation of WASI (WebAssembly System Interface), allowing Wasm modules to access system resources (files, environment variables, network via wasi-sockets) safely and sandboxed. Sandboxing: Wasm modules run in a memory-safe, capability-based sandbox with configurable resource limits (memory, CPU, filesystem access). Package management: Wasmer integrates with WAPM (WebAssembly Package Manager) for installing and running Wasm packages (wapm run python3, wapm run sqlite). WAPM hosts packages from publishers including Python, PHP, SQLite, and Nginx compiled to Wasm. Plugins: enables safe plugin architectures where untrusted code runs in isolated Wasm modules. Cross-compilation: compile once to Wasm, run on any platform. Pre-compiled Wasm modules avoid recompilation on target. Edge computing: deploy Wasm modules to CDN edges. Rust. MIT.