Open-source alternatives to Primer

This is a CSS UI framework and design system implementation used to build user interfaces that match the visual design of Office and Microsoft 365. It provides a standardized set of typography, color palettes, and grid layouts to ensure a consistent visual appearance across web applications. The framework is designed for enterprise design system implementation, specifically for Microsoft 365 UI development and the styling of Office add-ins. It includes a dedicated iconography library of standardized icons to represent common actions and objects. The system utilizes a token-driven design appr

WeUI is a mobile design system and CSS component framework providing a collection of pre-styled widgets and layout components for building mobile web applications. It functions as a mobile web UI library that enforces a consistent visual language and design language across web environments. The library utilizes a BEM styling system to prevent CSS conflicts and ensure modular component behavior. It provides a set of reusable styles and layout helpers that enable rapid prototyping of mobile web layouts through standardized buttons, dialogs, and navigation elements. The framework includes a mob

This project is a React UI component library and frontend UI kit designed to provide a collection of pre-styled user interface elements. It serves as a design system framework, offering standardized visual patterns to ensure a cohesive look and feel across different screens. The library focuses on design system implementation and frontend component architecture, allowing for the creation of modern websites and applications. It integrates directly into a React application workflow to accelerate the development of complex web layouts. The system utilizes a component-based abstraction and compo

Suit is a CSS component architecture framework and methodology designed for organizing styles using predictable naming conventions for components, descendants, and visual variations. It serves as a design system styling framework that maps application states and design variations to modular CSS rules. The system utilizes namespace-based CSS scoping to isolate component styles and prevent unintended side effects in global stylesheets. It also functions as a utility-first toolkit, providing a system for applying single-purpose layout and spacing rules to reduce code duplication. The methodolog

NES.css is an 8-bit CSS framework and styling system that transforms standard HTML elements into pixelated interfaces inspired by classic gaming consoles. It serves as a retro UI component library and toolkit for rendering text, borders, and icons with a blocky aesthetic. The framework uses pure CSS to emulate 8-bit graphics without relying on external images or JavaScript rendering. It implements pixel-art border simulations and integrates pixel-style web fonts to maintain a consistent gaming aesthetic across different browsers. The system provides a suite of game-themed interface elements,

ng-zorro-antd is an Angular UI component library that implements the Ant Design visual language. It provides a collection of pre-built interface elements and professional design system layouts for building web applications. The library is designed as a themable component framework, offering configuration options to modify the visual styles of interface elements. It also functions as an internationalized UI library with built-in support for translating interface elements into multiple languages. The project covers enterprise UI development and multilingual interface design. Its capability sur

PrimeReact is a comprehensive UI component library for building interactive user interfaces with React. It provides an accessible component suite, a form input framework, and a data visualization toolkit designed to meet accessibility standards through built-in keyboard navigation and focus management. The library features a themed design system that allows for visual customization via pre-defined skin sets or an unstyled mode. This unstyled mode decouples component behavior and accessibility logic from the presentation layer, enabling the implementation of custom corporate design systems. C

Skeleton is a design system and accessible UI component library built on Tailwind CSS. It provides a collection of pre-built interactive components with built-in accessibility and state management, alongside a CSS custom properties theme engine that enables runtime theme switching and dark mode support. The project distinguishes itself through its adaptive design system approach, using CSS custom properties to create themeable tokens that integrate directly with Tailwind's utility-first framework. This allows developers to build visual design systems with customizable colors, fonts, and aesth

BOOTSTRA.386 is a retro CSS framework and web UI kit designed to implement nostalgic user interfaces that mimic the aesthetic of vintage computer systems and old-school operating systems. It provides a collection of pre-styled components and styling engines to maintain a consistent legacy appearance across different screen sizes. The toolkit includes a customizable theme engine and a web-based interface for modifying visual properties and colors. It also features a responsive grid layout system that organizes web content into columns and rows that adapt to various device dimensions. The proj

Nord is a cross-platform design palette and CSS color system providing a curated set of dimmed pastel colors for building consistent user interfaces and code themes. It functions as a UI design framework that delivers a standardized collection of colors through multiple file formats for use in development tools and graphic design software. The system is defined by its dual-mode visual theme, which coordinates complementary light and dark color sets to maintain a consistent visual hierarchy across different brightness modes. It also includes a syntax highlighting theme that maps specific palet

Arco Design is a React UI component library and design system framework used to build professional web interfaces. It provides a collection of pre-built visual elements and layouts designed to maintain a consistent design language across applications. The system features a token-based theming engine that utilizes hierarchical design variables and CSS variables to enable granular visual customization. This allows for the modification of global and component-level styles through a dedicated theme editor or loader to align the interface with specific brand identities. The framework supports ent

This project is a minimalist visual theme and customizable CSS framework for Obsidian. It functions as a markdown layout engine and an adaptive user interface designed to remove interface clutter and create a distraction-free writing environment. The theme distinguishes itself through layout transformations that convert standard markdown tables and lists into card-based grids and visual galleries. It provides a system for transforming structured data into scannable visual representations and organizes consecutive images into column-based grids. The framework covers comprehensive interface ae

This project is a design system toolkit and component library that provides a framework-agnostic approach to building web interfaces. It centers on an HTML-first development model, utilizing standard markup and utility-based CSS classes to construct consistent, responsive layouts. The library is built upon the UIkit 3 framework, allowing for the integration of pre-styled interface elements while maintaining control over the underlying markup structure. It further extends these capabilities through web component encapsulation, using custom elements to provide modular and isolated interface log

Vuestic UI is a Vue 3 component library providing a collection of pre-made user interface elements. It serves as a responsive UI framework and a themed component system designed to speed up frontend development and maintenance. The toolkit features a centralized configuration system for global styling and dynamic branding, including a built-in dark mode. It includes an internationalized interface toolkit with native support for localization and translating application content for multiple languages. The library provides a set of accessible web components that meet accessibility standards for

inuit.css is a Sass-based CSS framework and design system tool focused on building scalable user interfaces. It serves as a modular preprocessor system that utilizes BEM architecture and OOCSS patterns to structure stylesheets into reusable components and layout abstractions. The framework distinguishes itself by separating structural layout logic from visual skinning, allowing for the creation of design-agnostic layout objects. It employs a configuration-driven build process where developers can use feature switches and variable overrides to inject design tokens and selectively include only

This project is a collection of accessible, reusable interface components built for the Svelte framework. It functions as a comprehensive design system implementation, providing a standardized toolkit for constructing responsive and inclusive user interfaces that adhere to established design language and accessibility guidelines. The library distinguishes itself through a deep integration with the Svelte framework, utilizing compiler-based transformations to optimize component rendering and reactive state synchronization. It features a robust theme management system that applies visual styles

Pico is a lightweight, classless CSS framework designed to provide consistent, accessible, and responsive visual defaults for web interfaces. By prioritizing semantic HTML tags, it allows developers to build clean, structured pages without the need for complex class names or heavy dependencies. The framework functions as a comprehensive design system that automatically applies styling to standard elements, ensuring that typography, spacing, and layout remain cohesive across different screen sizes. The framework distinguishes itself through a modular, variable-driven architecture that emphasiz

Spartan is a development framework and design system toolset that combines a headless UI component library with a full-stack application scaffolder. It provides accessible, unstyled primitives that separate behavioral logic from visual styling, while automating the creation of development environments with end-to-end type safety across API and database layers. The project distinguishes itself by utilizing a component distribution model that copies styled source files directly into the local codebase to prevent dependency-based style locking. It also functions as an AI context server, using a

css.gg is a collection of visual assets providing a CSS UI icon library and an SVG icon set. It delivers vector icons and glyphs through CSS classes, SVG sprites, and a library of styled components for web interfaces. The project includes a Figma UI asset pack to support the creation of high-fidelity prototypes and interface mockups. These design assets can be exported into external tools for prototyping and layout standardization. The system provides capabilities for embedding vector graphics, integrating typographic symbols, and managing design assets via API or NPM. It also supports the c

Bootswatch is a collection of pre-designed CSS themes and visual skins for the Bootstrap framework. It provides a set of stylesheets and tools to change the appearance of a website by replacing default styles with curated visual identities. The project includes a theme customizer for modifying colors, fonts, and structural style variables. It also provides a JSON API that allows external platforms to fetch theme settings and values for programmatic integration of visual styles. The system manages styling through a combination of pre-compiled static stylesheets and SASS-based compilation. It

shadcn-svelte is a collection of accessible and customizable user interface elements for Svelte applications. Rather than being distributed as a traditional dependency, these components are provided as source code that is copied directly into the project codebase. The library utilizes a registry-based distribution system, allowing users to install specific UI blocks and components via a command-line interface. This system uses JSON metadata to define dependencies and file paths, while a bootstrapping process automates the configuration of styles and CSS variables. The project integrates Tail

Fomantic-UI is a component-based CSS library and frontend design system used to build consistent, responsive user interfaces. It functions as a CSS framework and responsive UI toolkit, providing a structured approach to managing typography, color palettes, and spacing. The project enables the development of custom UI components and the implementation of unified design systems across web applications. It provides a variable-driven theme compilation process to customize visual styles and a build-time system to compile selected components into production CSS bundles. The toolkit covers a broad

This project is an advanced CSS learning curriculum consisting of starter files and final projects. It provides a collection of real-world implementations and a project gallery designed for mastering modern layout and styling techniques. The curriculum focuses on a modular approach to stylesheets using Sass variables and architecture. It emphasizes the block-element-modifier naming convention to create maintainable and reusable CSS. The material covers several core capability areas, including responsive web design using CSS Grid, Flexbox, and media queries. It also includes the development o

This project is a plugin for Tailwind CSS that provides a declarative utility library for managing web interface animations. It functions as a motion framework, enabling developers to apply fluid entrance and exit effects to elements directly through utility classes. The framework distinguishes itself by offering a comprehensive suite of motion controls that integrate with the Tailwind ecosystem. It supports granular configuration of animation properties, including timing, duration, delay, and iteration, while allowing for complex transformations like rotation, scaling, and opacity adjustment

WeUI is a mobile web UI library and design system consisting of CSS components and HTML templates. It is specifically designed to replicate the visual identity and interface of the WeChat messaging ecosystem, providing a standardized set of components to build responsive mobile web interfaces. The library functions as a stateless component system, utilizing a pure CSS architecture and HTML templates that rely on external JavaScript for interactivity. It employs a BEM-based class naming convention to manage component nesting and prevent style leakage across complex layouts. The framework incl

weui-wxss is a mobile design system and UI framework designed for the WeChat Mini Program development environment. It provides a collection of reusable components and predefined styles to ensure interfaces match the native WeChat look and feel. The library focuses on implementing a native WeChat user experience by translating mobile design mockups into working code using standardized visual guidelines. It manages the visual appearance of applications through a consistent set of stylesheets tailored for the WeChat runtime. The framework includes capabilities for style management and the imple

Space Station 14 is a C# multiplayer game and roleplay simulation framework. It is built upon an Entity-Component-System (ECS) game engine that separates logic into systems and data into components to manage complex entity interactions. The project functions as a grid-based physics simulator with a YAML data-driven prototype system for defining game objects. The project features a specialized 2D sprite rendering engine that maps server-side appearance data to client-side shaders. It implements a networking model with client-side prediction and dirty-flagged state synchronization to reduce inp