What are the top WebAssembly repos?

Popular WebAssembly repositories on GitHub, each answered in plain English for non-coders: what it is, its tech stack, and how to run it.

assemblyscript/assemblyscriptAssemblyScript is a compiler that turns TypeScript-like code into WebAssembly, so JS developers can write fast
webassembly/binaryenC++ library and toolkit for compiling and optimizing code to WebAssembly, used internally by Emscripten, Rust,