TinaCMS : Tina is an open-source site editing toolkit for React-based sites like Next.js & Gatsby to build content management directly into your website.
Strut : An HTML5 Presentation Editor. A GUI / Authoring Tool for ImpressJS and Bespoke.js
Source at https://github.com/tantaman/Strut
GatsbyJS : Gatsby is a modern framework for blazing fast websites, made with React and GraphQL.
A React-powered node editor and runtime engine. Build apps that are resilient to changing requirements by modeling your business logic as a JSON graph. Flume provides a sleek UI for creating and editing these graphs.