TypeScript 6.0

What is TypeScript 6.0?

TypeScript 6.0 is the last release built on JavaScript — and the bridge to TypeScript 7.0, which is being rewritten in Go for native speed and parallel type-checking. This release modernizes defaults (strict mode on, ESM-first, ES2025 target), adds built-in Temporal API types, Map.getOrInsert, and RegExp.escape, and deprecates legacy patterns that won't survive the native port. If you write TypeScript, the migration window to the native era starts now.

From the website

JavaScript With Syntax For Types.

TypeScript extends JavaScript by adding types to the language. TypeScript speeds up your development experience by catching errors and providing fixes before you even run your code.