p5.js

Tiptap is a headless, framework-agnostic rich text editor built on top of ProseMirror. It ships no UI of its own, instead exposing a composable extension system that lets developers build fully custom editing experiences in React, Vue, or vanilla JavaScript.

Slate is a completely customizable framework for building rich text editors in React. Rather than shipping a fixed editor, it provides a schema-less, plugin-driven core and a nested document model so developers can implement editors like Medium, Dropbox Paper, or Google Docs without fighting against built-in assumptions.

Trix is a WYSIWYG rich text editor from 37signals (creators of Rails) that powers writing in Basecamp. Rather than relying on contenteditable/execCommand directly, it treats the browser's editable surface as an I/O device, mapping input onto an internal document model and re-rendering to produce clean, consistent HTML.

wangEditor is an open-source, web-based rich text (WYSIWYG) editor written in TypeScript, popular in the Chinese developer community. It ships with framework integrations and a configurable toolbar for building content-editing experiences in the browser.

Plate is a TypeScript rich-text editor framework built on Slate and slate-react, offering a plugin system plus a large catalog of plugins, Radix UI-based headless primitives, and ready-made shadcn/ui components for assembling production editors.

TinyMCE is a highly customizable, framework-agnostic WYSIWYG rich text editor for the web, built on contentEditable with an extensive plugin and API ecosystem. It supports classic, inline, and distraction-free editing modes and ships official wrappers for React, Vue, and Angular.