Romans Cool Diagram Software (RCDS) is a free, open-source, browser-based diagram editor created by Roman Slack as an alternative to tools like Draw.io (diagrams.net), Lucidchart, and Figma. It is built for technical diagrams such as architecture diagrams, flowcharts, system designs, and network diagrams, with an emphasis on a modern, publication-ready aesthetic.
The application runs entirely in the browser, letting users create new projects or import existing ones from JSON and save their work to local browser storage. A central canvas with a configurable grid, snap-to-grid behavior, adjustable dimensions, and zoom control gives users precise control over layout and composition.
Elements are added from a toolbar and refined through an inspector panel for property editing, while finished diagrams can be exported as PNG, SVG, or JSON for backup, sharing, or further editing. By keeping the project open source and free, Roman Slack offers a lightweight, self-contained option for producing clean technical diagrams without subscription tooling.
Key Features
- Create, import, and save projects via JSON and browser storage
- Configurable canvas with adjustable width and height
- Grid system with toggle visibility and snap-to-grid
- Zoom control and direct on-canvas element selection
- Inspector panel for editing element properties
- Export to PNG, SVG, and JSON formats
Designed and built by Roman Slack, Lead AI Platform Engineer. See more of Roman Slack's work on the projects page or get in touch via the contact page.