Figma

Penpot is the first open-source design and prototyping platform. Built on open web standards (SVG), it allows real-time collaboration and is fully self-hostable. Feature-complete alternative to Figma for most UI/UX workflows.

Lunacy is a free graphic design software with built-in assets, icons, photos, and illustrations. Reads and writes Sketch files natively. Offline-first with cloud collaboration features.

Framer offers a generous free tier for individual designers with full prototyping capabilities, component libraries, and publish to web. Freemium model with no watermarks on free tier.

Plasmic is a visual page builder and design tool that integrates with existing codebases. Free tier supports unlimited projects with team collaboration for up to 2 members.

Quant-UX is an open-source research, usability, and prototyping tool. Features user testing analytics built-in, making it ideal for UX researchers alongside designers.

Pencil is an open-source GUI prototyping tool built for creating mockups in various formats including Android, iOS, and web. Includes built-in stencil collections for rapid wireframing.

Akira is a native Linux application built in Vala/GTK for UI and UX design. Designed specifically for Linux desktop users who need a native, performant design tool without web dependencies.