ReactPage (formerly ORY Editor) is a production-grade WYSIWYG page editor built in React. It provides a visual drag-and-drop interface for composing page layouts from a plugin system of content and layout cells. The editor stores its state as a structured JSON tree (not HTML), enabling versioning, migrations, and server-side rendering. It supports multi-language content, undo/redo, inline editing via Slate, and a read-only mode for lightweight rendering. The architecture is a monorepo with a core editor package, a rich set of content plugins (Slate rich text, image, video, spacer, divider, HTML5 video), a layout plugin (background with gradients/images), and a ReactAdmin integration. The editor is highly extensible: custom cell plugins can define their own renderers, controls (auto-generated forms via uniforms), cell styles, and data migrations. The Slate plugin itself is extensible via factory functions for marks, blocks, and data plugins. The project is used in production by several companies for CMS-like page building.