1# Introduction 2 3[Wasmtime][github] is a standalone runtime for WebAssembly, WASI, and the 4Component Model by the [Bytecode Alliance][BA]. 5 6[WebAssembly] (abbreviated Wasm) is a binary instruction format that is designed 7to be a portable compilation target for programming languages. Wasm binaries 8typically have a `.wasm` file extension. In this documentation, we'll also use 9the textual representation of the binary files, which have a `.wat` file 10extension. 11 12[WASI] (the WebAssembly System Interface) defines interfaces that provide a 13secure and portable way to access several operating-system-like features such as 14filesystems, networking, clocks, and random numbers. 15 16[The Component Model] is a Wasm architecture that provides a binary format for 17portable, cross-language composition. More specifically, it supports the use of 18interfaces via which components can communicate with each other. WASI 19is defined in terms of component model interfaces. 20 21Wasmtime runs WebAssembly code [outside of the Web], and can be used both as a 22command-line utility or as a library embedded in a larger application. It 23strives to be 24 25- **Fast**: Wasmtime is built on the optimizing [Cranelift] code generator. 26- **Secure**: Wasmtime's development is strongly focused on correctness and 27 security. 28- **Configurable**: Wasmtime uses sensible defaults, but can also be configured 29 to provide more fine-grained control over things like CPU and memory 30 consumption. 31- **Standards Compliant**: Wasmtime passes the official WebAssembly test suite 32 and the Wasmtime developers are intimately engaged with the WebAssembly 33 standards process. 34 35This documentation is intended to serve a number of purposes and within you'll 36find: 37 38* [How to use Wasmtime from a number of languages](lang.md) 39* [How to install and use the `wasmtime` CLI](cli.md) 40* Information about [stability](stability.md) and [security](security.md) in 41 Wasmtime. 42* Documentation about [contributing](contributing.md) to Wasmtime. 43 44... and more! The source for this guide [lives on 45GitHub](https://github.com/bytecodealliance/wasmtime/tree/main/docs) and 46contributions are welcome! 47 48[github]: https://github.com/bytecodealliance/wasmtime 49[BA]: https://bytecodealliance.org/ 50[Cranelift]: https://github.com/bytecodealliance/wasmtime/blob/main/cranelift/README.md 51[WebAssembly]: https://webassembly.org/ 52[WASI]: https://wasi.dev 53[outside of the Web]: https://webassembly.org/docs/non-web/ 54[issue]: https://github.com/bytecodealliance/wasmtime/issues/new 55[The Component Model]: https://github.com/WebAssembly/component-model 56