Deno Explained: JavaScript's Secure Second Runtime
Introduction Node.js (the very first batch's post) made JavaScript a server language — but its creator, Ryan Dahl, later listed regrets: no built-in TypeScript, a module system that drifted from web standards, and no security model (any script could read your files or the network). Deno, released in 2020, is his second attempt: a runtime for JavaScript and TypeScript that fixes those regrets by design, with security as the default rather than an afterthought. Secure by default, TypeScript built in Three design choices define Deno: Permissions — a Deno script runs with no access to files, network, or environment variables unless you explicitly grant it: deno run --allow-net --allow-read server.ts gives network and file-read access, and nothing else. A malicious or buggy dependency can't silently read your system. TypeScript out of the box — Deno runs TypeScript directly, with no build step or configuration, and includes a formatter, linter, and test runner built in (compare the...