[](https://docs.rs/tinywasm) [](https://crates.io/crates/tinywasm) [](./LICENSE-APACHE)
## Why TinyWasm?
- **Tiny**: TinyWasm is designed to be as small as possible without significantly compromising performance or functionality (< 4000 LLOC).
- **Portable**: TinyWasm runs on any platform that Rust can target, including `no_std`, with minimal external dependencies.
- **Safe**: No unsafe code is used in the runtime (`rkyv` which uses unsafe code can be used for serialization, but is optional).
## Status
TinyWasm passes all WebAssembly MVP tests from the [WebAssembly core testsuite](https://github.com/WebAssembly/testsuite) and is able to run most WebAssembly programs. Additionally, the current 2.0 Draft is mostly supported, with the exception of Fixed-Width SIMD and Memory64/Multiple Memories. See the [Supported Proposals](#supported-proposals) section for more information.
## Supported Proposals
**Legend**\
🌑 -- not available\
🚧 -- in development / partialy supported\
🟢 -- fully supported
| Proposal | Status | TinyWasm Version |
| -------------------------------------------------------------------------------------------------------------------------- | ------ | ---------------- |
| [**Mutable Globals**](https://github.com/WebAssembly/mutable-global/blob/master/proposals/mutable-global/Overview.md) | 🟢 | 0.2.0 |
| [**Non-trapping float-to-int Conversion**](https://github.com/WebAssembly/nontrapping-float-to-int-conversions) | 🟢 | 0.2.0 |
| [**Sign-extension operators**](https://github.com/WebAssembly/sign-extension-ops) | 🟢 | 0.2.0 |
| [**Multi-value**](https://github.com/WebAssembly/spec/blob/master/proposals/multi-value/Overview.md) | 🟢 | 0.2.0 |
| [**Bulk Memory Operations**](https://github.com/WebAssembly/spec/blob/master/proposals/bulk-memory-operations/Overview.md) | 🟢 | 0.4.0 |
| [**Reference Types**](https://github.com/WebAssembly/reference-types/blob/master/proposals/reference-types/Overview.md) | 🟢 | 0.7.0 |
| [**Multiple Memories**](https://github.com/WebAssembly/multi-memory/blob/master/proposals/multi-memory/Overview.md) | 🟢 | 0.8.0 |
| [**Memory64**](https://github.com/WebAssembly/memory64/blob/master/proposals/memory64/Overview.md) | 🚧 | N/A |
| [**Fixed-Width SIMD**](https://github.com/webassembly/simd) | 🌑 | N/A |
## Usage
See the [examples](./examples) directory and [documentation](https://docs.rs/tinywasm) for more information on how to use TinyWasm.
For testing purposes, you can also use the `tinywasm-cli` tool:
```sh
$ cargo install tinywasm-cli
$ tinywasm-cli --help
```
## Feature Flags
- **`std`**\
Enables the use of `std` and `std::io` for parsing from files and streams. This is enabled by default.
- **`logging`**\
Enables logging using the `log` crate. This is enabled by default.
- **`parser`**\
Enables the `tinywasm-parser` crate. This is enabled by default.
- **`archive`**\
Enables pre-parsing of archives. This is enabled by default.
With all these features disabled, TinyWasm only depends on `core`, `alloc` ,and `libm` and can be used in `no_std` environments.
Since `libm` is not as performant as the compiler's math intrinsics, it is recommended to use the `std` feature if possible (at least [for now](https://github.com/rust-lang/rfcs/issues/2505)), especially on wasm32 targets.
## Inspiration
Big thanks to the authors of the following projects, which have inspired and influenced TinyWasm:
- [wasmi](https://github.com/wasmi-labs/wasmi) - an efficient and lightweight WebAssembly interpreter that also runs on `no_std` environments
- [wasm3](https://github.com/wasm3/wasm3) - a high performance WebAssembly interpreter written in C
- [wazero](https://wazero.io/) - a zero-dependency WebAssembly interpreter written in go
- [wain](https://github.com/rhysd/wain) - a zero-dependency WebAssembly interpreter written in Rust
I encourage you to check these projects out if you're looking for more mature and feature-complete WebAssembly Runtimes.
## License
Licensed under either of [Apache License, Version 2.0](./LICENSE-APACHE) or [MIT license](./LICENSE-MIT) at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in TinyWasm by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.
**Note:** The GitHub repository contains a Submodule (`crates/tinywasm-parser/data`) which is licensed only under the [Apache License, Version 2.0](https://github.com/WebAssembly/spec/blob/main/test/LICENSE). This data is generated from the [WebAssembly Specification](https://github.com/WebAssembly/spec/tree/main/test) and is only used for testing purposes and not included in the final binary.
