github.com/tetratelabs/wazero@v1.7.1/README.md (about)

     1  # wazero: the zero dependency WebAssembly runtime for Go developers
     2  
     3  [![WebAssembly Core Specification Test](https://github.com/tetratelabs/wazero/actions/workflows/spectest.yaml/badge.svg)](https://github.com/tetratelabs/wazero/actions/workflows/spectest.yaml) [![Go Reference](https://pkg.go.dev/badge/github.com/tetratelabs/wazero.svg)](https://pkg.go.dev/github.com/tetratelabs/wazero) [![License](https://img.shields.io/badge/License-Apache_2.0-blue.svg)](https://opensource.org/licenses/Apache-2.0)
     4  
     5  WebAssembly is a way to safely run code compiled in other languages. Runtimes
     6  execute WebAssembly Modules (Wasm), which are most often binaries with a `.wasm`
     7  extension.
     8  
     9  wazero is a WebAssembly Core Specification [1.0][1] and [2.0][2] compliant
    10  runtime written in Go. It has *zero dependencies*, and doesn't rely on CGO.
    11  This means you can run applications in other languages and still keep cross
    12  compilation.
    13  
    14  Import wazero and extend your Go application with code written in any language!
    15  
    16  ## Example
    17  
    18  The best way to learn wazero is by trying one of our [examples](examples/README.md). The
    19  most [basic example](examples/basic) extends a Go application with an addition
    20  function defined in WebAssembly.
    21  
    22  ## Runtime
    23  
    24  There are two runtime configurations supported in wazero: _Compiler_ is default:
    25  
    26  By default, ex `wazero.NewRuntime(ctx)`, the Compiler is used if supported. You
    27  can also force the interpreter like so:
    28  ```go
    29  r := wazero.NewRuntimeWithConfig(ctx, wazero.NewRuntimeConfigInterpreter())
    30  ```
    31  
    32  ### Interpreter
    33  Interpreter is a naive interpreter-based implementation of Wasm virtual
    34  machine. Its implementation doesn't have any platform (GOARCH, GOOS) specific
    35  code, therefore _interpreter_ can be used for any compilation target available
    36  for Go (such as `riscv64`).
    37  
    38  ### Compiler
    39  Compiler compiles WebAssembly modules into machine code ahead of time (AOT),
    40  during `Runtime.CompileModule`. This means your WebAssembly functions execute
    41  natively at runtime. Compiler is faster than Interpreter, often by order of
    42  magnitude (10x) or more. This is done without host-specific dependencies.
    43  
    44  ### Conformance
    45  
    46  Both runtimes pass WebAssembly Core [1.0][7] and [2.0][14] specification tests
    47  on supported platforms:
    48  
    49  |   Runtime   |                 Usage                  | amd64 | arm64 | others |
    50  |:-----------:|:--------------------------------------:|:-----:|:-----:|:------:|
    51  | Interpreter | `wazero.NewRuntimeConfigInterpreter()` |   ✅   |   ✅   |   ✅    |
    52  |  Compiler   |  `wazero.NewRuntimeConfigCompiler()`   |   ✅   |   ✅   |   ❌    |
    53  
    54  ## Support Policy
    55  
    56  The below support policy focuses on compatibility concerns of those embedding
    57  wazero into their Go applications.
    58  
    59  ### wazero
    60  
    61  wazero's [1.0 release][15] happened in March 2023, and is [in use][16] by many
    62  projects and production sites.
    63  
    64  We offer an API stability promise with semantic versioning. In other words, we
    65  promise to not break any exported function signature without incrementing the
    66  major version. This does not mean no innovation: New features and behaviors
    67  happen with a minor version increment, e.g. 1.0.11 to 1.2.0. We also fix bugs
    68  or change internal details with a patch version, e.g. 1.0.0 to 1.0.1.
    69  
    70  You can get the latest version of wazero like this.
    71  ```bash
    72  go get github.com/tetratelabs/wazero@latest
    73  ```
    74  
    75  Please give us a [star][17] if you end up using wazero!
    76  
    77  ### Go
    78  
    79  wazero has no dependencies except Go, so the only source of conflict in your
    80  project's use of wazero is the Go version.
    81  
    82  wazero follows the same version policy as Go's [Release Policy][10]: two
    83  versions. wazero will ensure these versions work and bugs are valid if there's
    84  an issue with a current Go version.
    85  
    86  Additionally, wazero intentionally delays usage of language or standard library
    87  features one additional version. For example, when Go 1.29 is released, wazero
    88  can use language features or standard libraries added in 1.27. This is a
    89  convenience for embedders who have a slower version policy than Go. However,
    90  only supported Go versions may be used to raise support issues.
    91  
    92  ### Platform
    93  
    94  wazero has two runtime modes: Interpreter and Compiler. The only supported operating
    95  systems are ones we test, but that doesn't necessarily mean other operating
    96  system versions won't work.
    97  
    98  We currently test Linux (Ubuntu and scratch), MacOS and Windows as packaged by
    99  [GitHub Actions][11], as well compilation of 32-bit Linux and 64-bit FreeBSD.
   100  
   101  * Interpreter
   102    * Linux is tested on amd64 (native) as well arm64 and riscv64 via emulation.
   103    * MacOS and Windows are only tested on amd64.
   104  * Compiler
   105    * Linux is tested on amd64 (native) as well arm64 via emulation.
   106    * MacOS and Windows are only tested on amd64.
   107  
   108  wazero has no dependencies and doesn't require CGO. This means it can also be
   109  embedded in an application that doesn't use an operating system. This is a main
   110  differentiator between wazero and alternatives.
   111  
   112  We verify zero dependencies by running tests in Docker's [scratch image][12].
   113  This approach ensures compatibility with any parent image.
   114  
   115  -----
   116  wazero is a registered trademark of Tetrate.io, Inc. in the United States and/or other countries
   117  
   118  [1]: https://www.w3.org/TR/2019/REC-wasm-core-1-20191205/
   119  [2]: https://www.w3.org/TR/2022/WD-wasm-core-2-20220419/
   120  [4]: https://github.com/WebAssembly/meetings/blob/main/process/subgroups.md
   121  [5]: https://github.com/WebAssembly/WASI
   122  [6]: https://pkg.go.dev/golang.org/x/sys/unix
   123  [7]: https://github.com/WebAssembly/spec/tree/wg-1.0/test/core
   124  [9]: https://github.com/tetratelabs/wazero/issues/506
   125  [10]: https://go.dev/doc/devel/release
   126  [11]: https://github.com/actions/virtual-environments
   127  [12]: https://docs.docker.com/develop/develop-images/baseimages/#create-a-simple-parent-image-using-scratch
   128  [13]: https://github.com/WebAssembly/WASI/blob/snapshot-01/phases/snapshot/docs.md
   129  [14]: https://github.com/WebAssembly/spec/tree/d39195773112a22b245ffbe864bab6d1182ccb06/test/core
   130  [15]: https://tetrate.io/blog/introducing-wazero-from-tetrate/
   131  [16]: https://wazero.io/community/users/
   132  [17]: https://github.com/tetratelabs/wazero/stargazers