Why? For years we've had open formats for documents (PDF), images (PNG) and graphics (SVG). But user interfaces are still mostly locked inside design tools. And that was fine when humans were creating and consuming UIs. Now AI is also creating and consuming them. Today AI usually works with screenshots, editor-specific JSON, or tool-specific APIs. They work, but they weren't really designed for AI or for moving designs between different tools. So I started building . gui . The idea is si...