Deno

Deno v2.0 (2024/2025) focuses on Node.js Compatibility. It can now run most npm packages and package.json projects, removing the biggest barrier to entry.

When to Use

• Security: Sandbox by default. No file/net access unless explicitly allowed.
• All-in-One: Built-in linter, formatter, test runner, bundler.
• TypeScript: Native support. No config needed.

Core Concepts

Permission Model

deno run --allow-net --allow-read main.ts.

URL Imports (Legacy-ish)

import ... from "https://deno.land/...". v2 supports npm specifiers too.

Deno Deploy

The global edge network designed for Deno.

Best Practices (2025)

Do:

• Use jsr: The new JavaScript Registry (superset of npm).
• Use deno serve: High-performance HTTP server.
• Migrate Node apps: Try running deno run main.js on existing Node projects.

Don’t:

• Don’t rely heavily on node_modules: Use native Deno/JSR patterns where possible for speed.

References

• Deno Documentation