Dillinger is a cloud-enabled, online Markdown editor with live preview, export to Markdown, HTML, and PDF, and synchronization with cloud storage services including GitHub, Dropbox, Google Drive, OneDrive, and Bitbucket. Built with Next.js 14 (App Router), the application uses Monaco Editor for editing, Zustand for client-side state management with localStorage persistence, and markdown-it with a rich plugin chain for rendering. It features a modular architecture with API routes for OAuth flows and file operations per cloud provider, a versioned public REST API (v1) for rendering and export, and separate packages for a CLI tool and an MCP server for LLM integration. The codebase is well-organized with clear component separation (editor, preview, sidebar, modals, UI primitives), custom hooks per integration, and comprehensive unit and E2E test coverage. Auxiliary agent/skill files and design system CSVs exist in the repository but are development tools, not part of the application runtime.