Everything Open-Source.

Figma

Figma is a browser-based collaborative design tool, with it's own file-sharing community.

UI
Design Tool
Free Plan

Framer

Framer is a browser-based interactive design and prototyping tool.

UI
Design Tool
Free Plan

Adobe

Spectrum Design System

Design System
React
Open-Source

Alibaba

Ant Design System

Design System
React
Open-Source

Apple

Apple Developer Design Guidelines

Design System
React
Open-Source

Atlassian

Atlassian Design System

Design System
React
Open-Source

Blueprint

React-based UI toolkit for the web

Design System
React
Open-Source

Cloudflare

cf-ui Design System

Design System
React
Open-Source

Chakra UI

Simple, modular and accessible component library

Design System
React
Open-Source

Evergreen

React UI Framework for the Web

Design System
React
Open-Source

Firefox

Photon Design System

Design System
React
Open-Source

GitHub

Primer Design System

Design System
React
Open-Source

Gitlab

Pajamas Design System

Design System
React
Open-Source

Google

Material Design System

Design System
React
Open-Source

HubSpot

Canvas Design System

Design System
React
Open-Source

IBM

Carbon Design System

Design System
React
Open-Source

JetBrains

Ring UI

Design System
React
Open-Source

Pinterest

Gestalt Design System

Design System
React
Open-Source

Pluralsight

Pluralsight Design System

Design System
React
Open-Source

Priceline

Priceline One Design System

Design System
React
Open-Source

Salesforce

Lightning Design System

Design System
React
Open-Source

Shopify

Polaris Design System

Design System
React
Open-Source

WeWork

Plasma Design System

Design System
React
Open-Source

Balsamiq

An easy-to-use rapid low-fidelity UI wireframing tool.

UI
Wireframing
$$$

Color Box

An open-source tool for creating color palettes originally developed by Lyft's team.

Color
Palettes
Open-Source

Components.ai Color Scale

An open-source tool for creating color palettes.

Color
Palettes
Open-Source

Components.ai Gradients

An open-source tool for creating gradients.

Color
Gradients
Open-Source

Feather Icons

An open-source set of 24px React icons. Sets for Sketch and Figma available as well.

UI
Icons
MIT License

CSS.gg

Open-source CSS, SVG and Figma UI Icons available in SVG Sprite, styled-components, NPM & API.

UI
Icons
MIT License

Health Icons

An open-source set of healthcare-related icons.

UI
Icons
MIT License

Ionicons

Ionicons is a completely open-source icon set crafted for web, iOS, Android, and desktop apps.

UI
Icons
MIT License

Remix Icons

A set of open-source neutral style system symbols for designers and developers.

UI
Icons
Apache 2.0 License

The Noun Project

A massive and diverse collection of icons made by designers from all over the world.

UI
Icons
Free Plan

Jetbrains Mono

An open-source monospace font designed for developers. Looks great at large and small scale.

UI
Font
Open-Source

Inter

A beautiful open-source variable sans-serif font, intended for use on-screen.

UI
Font
Open-Source

Google Fonts

A huge library of free licensed font families, with APIs for easily importing and using the fonts.

UI
Font
Open-Source

GitHub

GitHub is a repository for development and version control using Git.

Code
Repo
Free

GitLab

GitLab is a repository for development and version control using Git.

Code
Repo
Free

Bootstrap

Featuring a responsive grid system, prebuilt components, and JavaScript plugins.

Code
CSS
Open-Source

Bulma

A framework that provides frontend components easily combined to build responsive web interfaces.

Code
CSS
Open-Source

Tailwind CSS

A utility-first CSS framework packed with classes that can be used directly in your markup.

Code
CSS
Open-Source

Stitches JS

The modern CSS-in-JS library with near-zero runtime, server-side rendering, and multi-variant support.

Code
CSS
Open-Source

Open Source Design

An open-source design community.

Community
Forum
Open-Source

Design Systems Slack

A Slack community focused on design systems.

Community
Slack
Design Systems

Friends of Figma

Figma's Slack workspace, open to all.

Community
Slack
UI Design