Diagrams.net (formerly draw.io) is a free, open-source diagramming application. It supports a wide variety of diagrams, including flowcharts, UML diagrams, mind maps, organizational charts, network diagrams, and more. Diagrams can be created and edited directly in the browser or via desktop apps, and can be saved in multiple formats, including SVG, PNG, JPEG, and PDF. It integrates with Google Drive, OneDrive, Dropbox, and GitHub.