This is the official Scratch 3.0 graphical user interface (scratch-gui), a React/Redux single-page application that provides the complete web-based editor for creating, editing, and running Scratch projects. It integrates tightly with the Scratch ecosystem (scratch-vm, scratch-blocks, scratch-render, scratch-storage, etc.) to deliver block-based programming, sprite/costume/sound management, stage rendering, hardware extensions, cloud variables, tutorials, and project save/load. The architecture is heavily modular with many Higher-Order Components (HOCs) and relies on a centralized Redux store. While the codebase is large and well-structured for its domain, it exhibits significant technical drift due to outdated dependencies (React 16, Redux 3, Jest 21) and reliance on deprecated lifecycle methods. The repository is being archived and migrated to the scratch-editor mono-repo, as announced in the README.