Svelte 4.0 Beta is out. The most important changes are the minimum requirement of Node 16, TypeScript 5 and Webpack 5 (although the use of Webpack is not recommended)

Svelte 4.0 focusses on structural improvements of the project and comes with better types for use in TypeScript. Even though the project, itself, is now moving to JSDoc (they say that this makes library development a lot faster). More impactful changes are expected in Svelte 5.