@bgl Different goals, really. AssemblyScript is its own statically-typed language that happens to look like TypeScript: it accepts a strict subset of the syntax, wants explicit types like i32/f64 rather than dynamic values, and doesn't implement JavaScript's actual object and prototype semantics. You write new code specifically within those constraints to get compact WebAssembly out. Oseo is trying to keep full ECMA-262 dynamic semantics, arbitrary shapes, any, all of it, and still reach native code, with types and JSDoc used only as opt-in hints that fall back to a compiled generic path whenever they're wrong. AssemblyScript trades JavaScript semantics for a clean path to WebAssembly; Oseo is betting it doesn't have to make that trade. Similar-looking syntax, close to opposite premises.