TipTap

TipTap is a ProseMirror based editor that integrates Yjs as the collaborative editing solution. It has a rich ecosystem of extensions and integrates well into web frameworks (React, Vue, ..).

Headless WYSIWYG Text Editor – Tiptap Editortiptap_editor

They have a great getting-started guide for collaborative editing with Yjs & TipTap:

Collaborative editing – Tiptap Editortiptap_editor