A fast, secure WebAssembly runtime built by the Bytecode Alliance with full WASI 0.2 and Component Model support.
Wasmtime is the reference runtime for both WASI and the WebAssembly Component Model, maintained by the Bytecode Alliance. The 45.0.0 release (May 21, 2026) is built on Rust 1.93.0 and continues to use the Cranelift code generator for near-native execution performance, alongside the Winch baseline compiler for instant, predictable cold starts. Wasmtime is production-grade and powers platforms like Fermyon Spin. WASI 0.3 support is expected in the upcoming 46.x line, broadening the component-model surface available to guests. Its embedding API supports Rust, C, C++, Python, .NET, and Go, making it one of the most versatile runtimes for server-side Wasm workloads.
A cross-platform WebAssembly runtime with WASIX, WASI 0.2 default, jco support, and a public package registry.
The zero-dependency WebAssembly runtime for Go — WebAssembly 2.0/3.0 capable, no CGO, with Component Model support.
An open-source framework for building event-driven serverless WebAssembly apps — manifest v3, expanded triggers, now part of Akamai.