Deno

Deno is a JavaScript and TypeScript runtime created by Ryan Dahl (the creator of Node.js) as a redesign of his original work, addressing what he saw as Node's mistakes. Deno emphasises secure-by-default execution, native TypeScript, web-standard APIs, and a more curated standard library.

Key differences from Node.js

• Secure by default. No network, file, or environment access unless granted with explicit flags (--allow-net, --allow-read).
• Native TypeScript. Runs .ts files directly with no separate build step.
• Web-standard APIs. fetch, WebSocket, URL, crypto, all browser-compatible.
• URL-based imports. Import modules from URLs (originally), with a built-in centralised registry (JSR) and npm compatibility via npm: specifiers.
• Single binary. Compile a Deno project to a self-contained executable with deno compile.

Ecosystem

• Deno Deploy: serverless edge platform from the Deno team
• Fresh: island-architecture web framework
• JSR: a JavaScript registry with first-class TypeScript and provenance metadata