Deno supports and encourages writing code in TypeScript but the way it works is: Deno bundles TypeScrit compiler, uses it to convert TypeScript to JavaScript and then executes the JavaScript.
It can also run JavaScript files directly.
Deno's runtime is a bunch of JavaScript APIs + TypeScript typings so that they can be understood by TypeScript code.
There's a great Software Engineering Daily podcast with Elio Rivero [0] (audio and transcript in link) that goes into depth on Deno, TypeScript, JavaScript support. It's interesting that compile time was the (TS) killer.
Deno supports and encourages writing code in TypeScript but the way it works is: Deno bundles TypeScrit compiler, uses it to convert TypeScript to JavaScript and then executes the JavaScript.
It can also run JavaScript files directly.
Deno's runtime is a bunch of JavaScript APIs + TypeScript typings so that they can be understood by TypeScript code.