What is WebAssembly?
Compiled WebAssembly code can be run within the browser or Node.js. Therefore client and server can profit from WebAssembly's performnace boost. Yet, WebAssembly
Projects using WebAssembly
Stockfish, the strong chess engine is ported in WebAssembly using C++. The engine is used on chess-related websites like Lichess and runs both in the browser and backend.
Figma is a software for drafting UIs in collaboration, entirely in the browser. WebAssembly is used to accelerate calcuations, needed for the rendering.
PyScript is a Python interpreter and environment for the browser. It was written entirely in WebAssembly and enables developers to use libraries like Numpy in the browser.
The good thing about WASM is you can choose your entry-point. A lot of modern programming languages can be compiled to WebAssembyl, no matter if you use Go, Rust, C++ or even TypeScript.
As the source for the WAT-introduction especially, the Mozilla documentation is used - linked below.