we can do both. In JIT mode, we XHR for them and compile them on the fly. In AOT mode, we do that at build time and turn the templates into TS code, which we can then typecheck (thus giving you typechecking against templates) - the benefit of this is you don't have to ship the compiler code to the browser, don't pay the cost of runtime compilation, and the generated code is monomorphic and thus highly optimizable in browser VMs.