# Introduction AssemblyScript compiles a variant of TypeScript (opens new window) (a typed superset of JavaScript) to WebAssembly (opens new window) using Binaryen (opens new window), looking like: export function fib(n: i32): i32 { var a = 0, b = 1 if (n > 0) { while (--n) { let t = a + b a = b b = t } return b } return a } It is similiar to TypeScript but with WebAssembly types, has some constra