AssemblyScript

AssemblyScript is a TypeScript based programming language that is optimized for, and statically compiled to, WebAssembly. It resembles ECMAScript and JavaScript but adds static data types, and its type system closely reflects that of WebAssembly. The reference compiler, asc, is built on the Binaryen toolchain and is distributed through the npm package manager. The language is developed by the AssemblyScript Project with help from its community, and it gives developers who already know JavaScript a familiar way to target WebAssembly. Because it is mostly a subset of TypeScript, a program can in principle be compiled to both JavaScript and WebAssembly. It also exposes low level intrinsics that map directly to WebAssembly instructions. By May 2025 more than 29,000 projects hosted on GitHub were written wholly or partly in it, and Webpack adopted it in 2021 to speed up hash calculations.