Open-source alternatives to Yoga

This library is a portable, header-only engine designed for calculating the geometric positions and dimensions of nested rectangular elements. It provides a recursive stacking-box model to determine interface coordinates, serving as a lightweight solution for two-dimensional layout calculations in C99 or C++ environments. The engine distinguishes itself through its focus on portability and resource efficiency. It utilizes a dependency-free memory abstraction that allows developers to override default allocation and assertion routines, making it suitable for specialized or restricted computing

Taffy is a layout engine that calculates the size and position of user interface components. It is a language-agnostic tool that computes element geometry using Flexbox and Grid algorithms. The engine operates on custom tree structures and node storage through a trait-based interface. This design allows it to be integrated into various programming languages and custom memory management systems. The system handles UI layout computation, including leaf node measurement and floating point pixel snapping to prevent blurring on displays. It utilizes layout result caching to avoid redundant calcul

This is a layout library for Android applications that implements the CSS Flexible Box layout model. It provides a view container and engine that arrange child views by distributing space and aligning content according to a flexible box model. The framework enables the creation of responsive user interfaces that automatically adjust element positioning, wrapping, and growth based on available screen dimensions and orientations. The system includes capabilities for adaptive layout workflows, dynamic element alignment, and a virtualized rendering system for recycling views to display large dat

This project is a curated knowledge base and technical reference for professional web styling. It serves as a comprehensive guide to modern CSS best practices, focusing on techniques that leverage native browser capabilities to create efficient, maintainable, and scalable stylesheets. The collection emphasizes the use of declarative style logic and modern layout engines to replace brittle, imperative approaches. By prioritizing native pseudo-class state management, logical property mapping, and relative unit scaling, the guide demonstrates how to build responsive interfaces that remain consis

This project is a cross-platform user interface framework that maps mobile-native component primitives to standard web elements. It enables developers to build consistent applications that function across both mobile and web environments by providing a unified library of components and shared logic. The framework distinguishes itself through a specialized style engine that converts JavaScript object-based declarations into optimized, scoped CSS at runtime. It also features a responsive layout engine that implements a flexbox-based system, ensuring that interfaces adapt dynamically to differen

Magic of CSS is a structured tutorial series that teaches web developers advanced CSS layout, typography, and animation techniques through hands-on examples. The course covers the full spectrum of CSS capabilities, from foundational box model and positioning concepts to sophisticated animation and interactive state management, all without relying on JavaScript. The series distinguishes itself by teaching practical, real-world CSS patterns such as inline-block justified grids, percentage-based absolute positioning, table-display vertical centering, and letter-span styling techniques. It demons

ComponentKit is a declarative UI framework for building iOS interfaces through composition of small, reusable components. It provides a structured approach to constructing user interfaces where each component is defined as an immutable, pure function of its inputs, enabling predictable rendering and state management. The framework supports both stateless and stateful components, with controllers that can be attached to manage persistent state across component updates. The framework distinguishes itself through its component architecture that emphasizes explicit data flow and compile-time safe

ReactXP is a framework for building cross-platform mobile and web applications from a single codebase using React. It provides a declarative interface that maps to different native implementation sets depending on the target environment. The project enables consistent visual experiences across operating systems through a flexbox-based layout engine, a virtual stack for navigation management, and a unified native-bridge API for accessing system services. It distinguishes itself with specialized capabilities for declarative animation orchestration, platform-specific logic resolution, and an aut

Valdi is a cross-platform native UI framework that compiles declarative TypeScript code into native platform views. It functions as a declarative UI engine and multi-platform frontend toolchain designed to achieve high performance by avoiding web views. The framework features a native bridge binding tool that generates type-safe bindings between TypeScript and native languages, allowing direct access to platform APIs. It supports a hot-reload development workflow, enabling real-time updates to the user interface across platforms without requiring full project recompilation. The system includ

Texture is an iOS framework for building user interfaces that render on background threads using thread-safe node abstractions. It provides an asynchronous display node architecture that constructs and composites view hierarchies off the main thread, then synchronises the final bitmap for presentation, enabling smooth and responsive apps. The framework replaces UIKit's standard view system with node-based hierarchies that can be created, configured, and mutated on any queue without locking the main thread. The framework distinguishes itself through a precomputed rendering pipeline that decode

Rebass is a React design system library that provides a collection of theme-driven, responsive UI primitives. It functions as a theme-based layout engine, using a set of stateless components to standardize spacing, typography, and colors across a user interface. The library distinguishes itself by mapping style properties to a central design theme through a styled-system approach. This allows for responsive style mapping where components automatically adapt their appearance based on screen size and provides the ability to swap underlying HTML elements while preserving styling logic to maintai

Floem is a native desktop UI framework and cross-platform toolkit for building high-performance user interfaces. It functions as a reactive UI library that uses a signal-based state management system to automatically synchronize the interface with data changes via lightweight observable primitives. The framework utilizes a GPU-accelerated rendering engine to ensure visual consistency and high performance across different desktop operating systems. It features a layout engine based on flexible box and grid models to create responsive screens that adapt to various window sizes. The toolkit cov

This project is a collection of React components that implement a responsive grid system using CSS Flexbox and CSS Modules. It provides reusable building blocks for constructing fluid interfaces that organize page content into flexible rows and columns, which automatically adjust their size and alignment based on viewport dimensions. The library distinguishes itself by decoupling style definitions from component logic, which facilitates consistent rendering across both server-side environments and client-side runtimes. By utilizing CSS Modules, it encapsulates styles into local scopes to prev

Opentui is a terminal user interface framework for building interactive command line applications. It provides a component-based system featuring a flexbox layout engine, a virtual node component tree, and a low-level 2D cell array renderer. The project is distinguished by a sophisticated keyboard binding engine that maps complex multi-stroke sequences and chords to named commands using prioritized, reactive layers. It also implements a plugin architecture that allows external modules to inject custom UI components into designated layout slots and extend input logic at runtime. Its capabilit

MovieSwiftUI is a movie discovery application built with SwiftUI that integrates with the MovieDB API to retrieve and display movie information, ratings, and metadata. It functions as a cross-platform Apple application, providing a consistent user experience across iOS and macOS from a single codebase. The project implements a reactive data flow using Combine to synchronize global application state with the user interface. It employs a unidirectional data flow and a centralized store to maintain a single source of truth across different screens and components. The application utilizes declar

This project is a cross-platform mobile UI library and design system built for the React Native framework. It provides a collection of styleable and reusable interface components to ensure visual consistency across different mobile operating systems. The framework includes a specialized tool for transforming raw HTML strings into native mobile components using custom element rendering and style overrides. It also features a remote update system that allows interface changes and new features to be pushed directly to devices without requiring a full application store release. The library cover

This project is a browser-based collaborative design platform that provides a comprehensive workspace for interface design, interactive prototyping, and design system management. It functions as a vector graphics editor that enables teams to create, manage, and iterate on designs in real-time, utilizing a component-based inheritance model to ensure consistency across complex projects. The platform distinguishes itself through a deep integration of design and development workflows. It features a specialized developer handoff workspace that allows for the inspection of design properties, precis

Rich is a comprehensive library for building sophisticated command-line interfaces and terminal applications. It provides a robust console formatting engine and a layout framework that enables developers to render rich text, syntax-highlighted code, and complex data structures directly in the terminal. By utilizing a recursive constraint-based layout engine, the library allows for the creation of hierarchical grids, panels, and trees that maintain their structure even as terminal dimensions change. What distinguishes the library is its ability to manage persistent, real-time terminal interfac

FigmaToCode is a design-to-code converter and frontend code generator that transforms Figma design files into responsive source code. It functions as a multi-platform UI compiler, mapping visual design elements to structural constraints for web and mobile environments. The system supports multi-target syntax emission to produce code for HTML, Tailwind CSS, Flutter, and SwiftUI. It automates frontend styling by converting design system variables and visual effects into theme-consistent code across these different frameworks. The tool handles responsive UI implementation by translating design

This project is a comprehensive collection of frontend development best practices and standards. It provides guides for writing semantic HTML, efficient CSS, and functional JavaScript to improve overall web performance and accessibility. The repository establishes frameworks for modern CSS architecture, focusing on specificity management and the use of Flexbox and Grid for predictable layouts. It outlines patterns for functional JavaScript programming, emphasizing the use of pure functions and composition to reduce execution time and dependency bloat. The guidelines cover several core capabi

This project is a responsive layout framework for Angular that provides a system of directives to create adaptive user interfaces using CSS Flexbox and CSS Grid. It includes specialized libraries for managing flexible box alignment and structuring complex two-dimensional page grids. The framework features a breakpoint monitoring service to programmatically observe media query changes and trigger logic when viewport dimensions cross defined boundaries. To optimize performance, it includes a build-time CSS generator that uses SASS mixins to create static media query stylesheets, reducing the ne

Duilib is a Windows UI library and custom rendering engine designed for building high-performance graphical user interfaces for PC client software. It functions as a DirectUI framework that allows for the creation of bespoke layouts and tailored interface elements without relying on standard operating system controls. The framework implements a direct user interface approach to render custom graphical elements. This allows for the design of non-standard visual layouts for desktop applications, including those that require high-performance rendering for resource-heavy software. The system cov

RmlUi is a cross-platform UI renderer and middleware library that enables the creation of user interfaces using a subset of HTML and CSS. It functions as a rendering-agnostic layer designed to integrate web-standard layout and styling into custom game engines and embedded applications. The framework is distinguished by its integration of Lua for dynamic logic and control, as well as a specialized toolkit for rendering SVG images and Lottie animations. It utilizes a pluggable rendering backend that decouples geometry generation from the final display, allowing it to generate textured geometry

Litho is an Android declarative UI framework and component library used to build user interfaces through a declarative API and immutable state. It functions as an asynchronous layout engine that maps components to a structured view hierarchy to automate view updates. The framework optimizes rendering performance by computing element positions on background threads to prevent blocking the main UI thread. It further improves efficiency by flattening nested view hierarchies and caching layout results. The system includes capabilities for state reconciliation, component recycling, and the render

Azul is a native desktop application builder and UI toolkit for creating high-performance graphical user interfaces. It utilizes a functional and reactive programming model for managing layout and state, enabling the development of native software through a CSS-based toolkit. The framework is distinguished by its use of the WebRender engine to provide GPU-accelerated rendering. This allows the system to display complex user interface elements with high efficiency and speed by leveraging hardware acceleration. The project enables the design of desktop interfaces using a document object model

This library provides a framework for constructing professional PDF documents using declarative component syntax. It functions as a document engine that transforms component trees into structured files, allowing developers to define layouts, headers, footers, and margins through standard component structures rather than proprietary markup languages. The tool distinguishes itself by enabling server-side synthesis of dynamic data, which allows for the automated generation of personalized documents from live information sources. It maps web-standard styling and layout properties into the fixed-p

Gosub-engine is an HTML5 browser engine and web rendering pipeline that parses HTML5 and CSS3 to compute layout and render web content to pixels. It functions as a JavaScript runtime environment with a virtual machine and event loop for handling dynamic logic and asynchronous tasks. The system also includes a web storage manager for persisting cookies, local storage, and session storage. The project features a headless browser renderer capable of generating page images or extracting plain text without a visible window. It supports cross-platform graphics rendering through pluggable CPU and GP