FigmaOP

Managing the assets of design systems in Sketch is complex, error-prone and time consuming. Sketch is scriptable, but the API often changes. React provides the perfect wrapper to build reusable documents in a way already familiar to JavaScript developers.

UX guidelines, HTML/CSS framework, and Angular components working together to craft exceptional experiences. Start building with our HTML/CSS framework and rapidly go from prototype to production.

Sizzy is a tool for developing responsive websites crazy-fast. It allows you to preview a URL on multiple devices at once, filter the devices, zoom them in and out, and more.

Create dynamic, cross-platforms UIs using design tools, code, or both.

Gravit is a design tool for Mac, Windows, Linux, ChromeOS and the Browser made in the spirit for Freehand and Fireworks. It is completely written in HTML5, Javascript and CSS3. Gravit consists of the core engine called "Infinity", the actual Application and the core Module called "Gravit".

It is built for the purpose of providing a free and open-source GUI prototyping tool that people can easily install and use to create mockups in popular desktop platforms.

It is a free & open-source developer toolkit for expressing visual styles that can be shared across codebases, native platforms, and teams. It radically lowers the cost of delivering a consistent visual identity across native apps & websites.

It provides the same flexibility as your favorite image editor but also writes semantic HTML and remarkably succinct CSS. It's time to expect more from a web design tool.

A browser extension for coders to measure screen dimensions. Currently only available for Chrome. Download from the Product Website or the Chrome Webstore.

Interactive field-aligned mesh generator.

It is an open-source, browser-based 3D graphics suite. You can edit scenes and materials, design effects and shaders, code behaviours, and share your work - all within a browser using standard web technologies.

It is a toolkit that simplifies the creation of rich and interactive 2D or 3D experiences for any device from mobile to desktop to AR/VR. It gives you general-purpose HTML Elements for defining 2D or 3D scenes rendered with CSS3D, WebGL, or both mixed together.

It is a free and open source design presentation and collaboration platform. It has an Intuitive drag&draw interface.

It is an open-source design system for your next travel project. It is a React component library that provides developers with the easiest possible way of building Kiwi.com’s products.

It is an open-source UI design tool to create and maintain Web Components. Create components visually and use them with any framework, or with vanilla HTML/JavaScript.

It provides the open-source building blocks to design and implement consistent, accessible, and delightful product experiences.

It is an open-source platform to manage design templates directly in code, making it easy to create the building blocks of your app. It will run a visual editor of your theme and then directly export your design tokens to.js, .ts, .css, .scss, .json.