Open-source alternatives to Yoga

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

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

This project is a high-performance, lightweight C graphics library designed for creating interactive user interfaces on resource-constrained embedded hardware. It functions as a comprehensive framework that provides a widget toolkit, a rendering engine, and hardware-agnostic drivers to support the development of graphical displays on microcontrollers and embedded systems. The framework distinguishes itself through a flexible, object-oriented widget hierarchy and a declarative layout engine that supports responsive design patterns like flexbox and grid systems. It enables developers to synchro

This project is a terminal user interface library for Node.js, designed to facilitate the construction of interactive command-line applications. It provides a comprehensive toolkit of high-level widgets that abstract complex terminal escape codes and rendering logic, allowing developers to build functional interfaces using reusable components. The framework distinguishes itself by implementing a box-model-based layout engine and a virtual DOM-style reconciliation system. These mechanisms enable responsive design patterns—such as percentage-based sizing and relative positioning—to function wit

AsyncDisplayKit is an asynchronous UI framework and performance library for iOS. It provides a collection of performant alternatives to standard views, allowing developers to build responsive interfaces by offloading layout and rendering tasks to background threads. The framework is centered around a declarative layout engine based on a flexbox model, which calculates element positions and sizes asynchronously. It utilizes a node-based abstraction to wrap native views, enabling the instantiation and configuration of UI hierarchies on background threads to prevent main thread blocking. The sy

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

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

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

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

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

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

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

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

Flexibility is a JavaScript layout engine and CSS compatibility layer that functions as a polyfill for the CSS Flexbox specification. It simulates flexible box layout behavior in web browsers that do not natively support the specification. The project achieves cross-browser layout consistency by implementing a programmatic system to calculate and apply alignment, direction, and wrapping properties to DOM elements. It provides utilities for both the application and extraction of these layout styles to manage the visual structure of a page. The engine operates through DOM tree traversal and ma

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

Brick Design is a low-code page builder framework used to create drag-and-drop visual editors that generate production-ready layout and styling code for user interfaces. It functions as a visual layout engine and UI component orchestrator, providing the tools necessary to manage component constraints, nesting rules, and visual property configurations. The framework includes a dynamic template generator that utilizes logic rendering and expression variables to create reusable, data-driven page templates. It also operates as a multi-device design tool, offering viewport switching and adaptive s

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 project is a comprehensive guide for Python development and application deployment. It provides standardized patterns for coding standards, environment configuration, and the management of language runtimes and package managers across multiple operating systems. The guide features a taxonomic mapping of libraries and third-party tools, organizing curated solutions to match specific technical problems. It establishes preferred tools and patterns for developers while offering alternative options based on project requirements. Coverage extends to the full development lifecycle, including d

tview is a library for building interactive text-based user interfaces in Go. It functions as a toolkit for managing event loops, user input, and screen rendering, providing a framework of pre-built widgets and an integrated layout engine for creating command-line applications. The project distinguishes itself through a comprehensive layout system that uses grid and flexbox models to create responsive designs. It also supports UI layer stacking to manage multiple screens and modal overlays. The framework includes a diverse suite of interactive components for data display, such as tables and

QuestPDF is a C# PDF generation library and layout engine used to create structured documents, reports, and invoices. It utilizes a fluent API and a component-based layout approach to convert code into high-fidelity PDF and XPS files. The library distinguishes itself with a dedicated layout debugger that provides real-time previews, hot-reload capabilities, and visual boundary tools to map rendered elements back to source code. It also functions as an accessibility tool, providing semantic tagging and navigational aids to ensure documents comply with international accessibility and archival s

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

This project is a plugin-based WYSIWYG document layout engine and rich text editor that uses Canvas and SVG for rendering. It functions as a collaborative editor utilizing conflict-free replicated data types to enable real-time synchronization across multiple users. The system serves as an interactive form builder, allowing for the embedding of input controls such as checkboxes and date pickers directly into documents. It is designed for high-fidelity output, ensuring the visual representation during editing matches the final format for PDF and image exports. The editor covers broad capabili

A framework for building Mobile cross-platform UI

This project is a cross-platform mobile framework tutorial and JavaScript mobile app curriculum designed to teach the development of iOS and Android applications. It provides a structured educational guide and a set of lessons covering project bootstrapping, state management, and declarative user interface structures. The curriculum includes specific guides on mobile native bridge integration, providing tutorials on how to connect custom platform code to a cross-platform framework to access device-specific system APIs and hardware. The course covers the implementation of responsive mobile us

KMP-Awesome is a curated directory and resource index for the Kotlin Multiplatform ecosystem. It serves as a centralized hub for developers to discover libraries, frameworks, and tools designed to streamline the creation of shared codebases for mobile, desktop, and web applications. The project distinguishes itself by organizing a comprehensive collection of solutions that address the core challenges of cross-platform development. It highlights resources for implementing shared business logic, declarative user interface components, and type-safe data persistence layers. By providing a structu

Firefox is a cross-platform web browser engine designed to render web content, execute JavaScript, and manage secure browsing sessions. It utilizes a multi-process isolation architecture that distributes browser tasks across independent operating system processes to ensure stability and prevent site-specific failures from impacting the entire application. The engine incorporates a sandboxed execution environment to restrict web content and untrusted scripts to isolated memory compartments, enforcing security policies that prevent unauthorized access to system resources. The project distinguis