Wasmi does not directly compete with the large JIT engines such as Wasmtime and V8. Instead, Wasmi tries to fit perfectly into its niche. Its main purpose is th

Wasmi does not directly compete with the large JIT engines such as Wasmtime and V8. Instead, Wasmi tries to fit perfectly into its niche. Its main purpose is that it is very easy to embed and provides great performance for those use-cases. As detailed in the article, Wasmi is already used a lot for plugin systems, as game engine, as engine for executing smart contracts, and even as engine to run apps in experimental operating systems that have native Wasm support. It is also useful for cloud hosts that do not trust their inputs but need fast startup times and deterministic execution. Furthermore, there are platforms such as iOS that outright forbid using JITs, so interpreters are the only option. Fun fact: Wasm interpreter usually can even be embedded into Wasm environments themselves by compiling them to Wasm. Wasmi ran inside Wasmtime when it was used at Parity Technologies. This allowed them to hot-patch the Wasm runtime (Wasmi) without downtime.