wasmtime

A standalone runtime for WebAssembly

A Bytecode Alliance project

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## Installation The Wasmtime CLI can be installed on Linux and macOS with a small install script: ```sh $ curl https://wasmtime.dev/install.sh -sSf | bash ``` Windows or otherwise interested users can download installers and binaries directly from the [GitHub Releases](https://github.com/bytecodealliance/wasmtime/releases) page. ## Example If you've got the [Rust compiler installed](https://www.rust-lang.org/tools/install) then you can take some Rust source code: ```rust fn main() { println!("Hello, world!"); } ``` and compile/run it with: ```sh $ rustup target add wasm32-wasi $ rustc hello.rs --target wasm32-wasi $ wasmtime hello.wasm Hello, world! ``` ## Features * **Lightweight**. Wasmtime is a standalone runtime for WebAssembly that scales with your needs. It fits on tiny chips as well as makes use of huge servers. Wasmtime can be [embedded] into almost any application too. * **Fast**. Wasmtime is built on the optimizing [Cranelift] code generator to quickly generate high-quality machine code at runtime. * **Configurable**. Whether you need to precompile your wasm ahead of time, generate code blazingly fast with Lightbeam, or interpret it at runtime, Wasmtime has you covered for all your wasm-executing needs. * **WASI**. Wasmtime supports a rich set of APIs for interacting with the host environment through the [WASI standard](https://wasi.dev). * **Standards Compliant**. Wasmtime passes the [official WebAssembly test suite](https://github.com/WebAssembly/testsuite), implements the [official C API of wasm](https://github.com/WebAssembly/wasm-c-api), and implements [future proposals to WebAssembly](https://github.com/WebAssembly/proposals) as well. Wasmtime developers are intimately engaged with the WebAssembly standards process all along the way too. [Cranelift]: https://github.com/bytecodealliance/wasmtime/blob/main/cranelift/README.md [embedded]: https://bytecodealliance.github.io/wasmtime/lang.html ## Language Support You can use Wasmtime from a variety of different languages through embeddings of the implementation: * **[Rust]** - the [`wasmtime` crate] * **[C]** - the [`wasm.h`, `wasi.h`, and `wasmtime.h` headers][c-headers] * **[Python]** - the [`wasmtime` PyPI package] * **[.NET]** - the [`Wasmtime` NuGet package] * **[Go]** - the [`wasmtime-go` repository] [Rust]: https://bytecodealliance.github.io/wasmtime/lang-rust.html [C]: https://bytecodealliance.github.io/wasmtime/examples-c-embed.html [`wasmtime` crate]: https://crates.io/crates/wasmtime [c-headers]: https://bytecodealliance.github.io/wasmtime/c-api/ [Python]: https://bytecodealliance.github.io/wasmtime/lang-python.html [`wasmtime` PyPI package]: https://pypi.org/project/wasmtime/ [.NET]: https://bytecodealliance.github.io/wasmtime/lang-dotnet.html [`Wasmtime` NuGet package]: https://www.nuget.org/packages/Wasmtime [Go]: https://bytecodealliance.github.io/wasmtime/lang-go.html [`wasmtime-go` repository]: https://pkg.go.dev/github.com/bytecodealliance/wasmtime-go ## Documentation [📚 Read the Wasmtime guide here! 📚][guide] The [wasmtime guide][guide] is the best starting point to learn about what Wasmtime can do for you or help answer your questions about Wasmtime. If you're curious in contributing to Wasmtime, [it can also help you do that][contributing]!. [contributing]: https://bytecodealliance.github.io/wasmtime/contributing.html [guide]: https://bytecodealliance.github.io/wasmtime --- It's Wasmtime.