What is WebAssembly?

WebAssembly is a technology that allows you to compile application code written in pretty much any language (including Rust, C, C++, JavaScript, and Go) and run it inside sandboxed environments. WebAssembly is often known as just "wasm".

WebAssembly originated as a successor to asm.js, a low-level subset of JavaScript, and Google Native Client (NaCl), a technology to run a subset of native code in a sandboxed environment within the browser.

WebAssembly itself started in 2015, with a first release of the specification in 2017. By 2019 it became an official web standard with implementations across all major browsers.

Since then it became a compilation target for a wide variety of programming languages, gained usage across the web and other execution environments and got several independent runtime implementations inside and outside of browsers

Contrary to what the name might make you believe it is not tied to the web only. But the web is where it originated.

In the next chapters you will learn what WebAssembly looks like and where it is used.