Open-source alternatives to React Tetris

Kotlinx.collections.immutable is a persistent data structure library for Kotlin that provides immutable lists, sets, and maps for state management. It enforces strict immutability by exposing read-only interfaces that block unauthorized modifications at compile time, while persistent structural sharing allows modified copies to efficiently reuse underlying memory storage with the original collection. Multiple insertions and removals can be batched through temporary mutable builder interfaces to instantly produce new persistent collections without intermediate allocations. Additionally, stand

Draggable is a JavaScript library for implementing draggable elements and sortable lists within a web browser. It provides a functional toolset for creating accessible drag and drop interfaces and a mechanism for dynamically swapping, sorting, and reordering HTML elements in real time. The library features a cross-input interaction layer that unifies mouse, touch, and force-touch events into a single stream for consistent behavior across different devices. It specifically includes tools for providing screen reader feedback and assistive technology support to ensure drag operations are accessi

This project is a collection of reusable React hooks designed to wrap browser APIs, manage state persistence, and handle DOM observation. It provides a consistent interface for integrating native browser capabilities directly into the React component lifecycle. The library includes specialized toolkits for monitoring the browser environment, such as window resizing, network connectivity, and viewport visibility. It also provides mechanisms for managing execution timing through debouncing, throttling, and the control of timeouts and intervals. Additional capabilities cover state management wi

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

Bareiron is a minimalist environment for hosting multiplayer game servers on low-power, memory-constrained devices. It functions as a Minecraft server optimizer designed to provide basic connectivity for remote players while operating on embedded hardware with limited system resources. The software includes a hardware performance tuner that allows for the disabling of intensive game mechanics and resource-heavy features to prevent system crashes. It also incorporates a network traffic controller to adjust broadcast frequencies and tick rates, reducing bandwidth consumption and lag. The syste

Ramda is a functional JavaScript standard library and toolset for immutable data transformation and composition. It provides a comprehensive suite of pure utility functions designed to enable declarative data processing pipelines. The library is distinguished by its use of automatic function currying and a data-last argument order. These design patterns allow multi-argument functions to be partially applied, simplifying the construction of processing chains where data is passed through a sequence of operations. The toolkit covers broad data manipulation capabilities, including list processin

EpicEditor is a JavaScript-based Markdown editor designed as an embeddable UI component for web applications. It functions as a local-first content manager, utilizing browser local storage for automatic draft saving and offline content persistence. The editor is distinguished by its use of iframes to isolate styles, preventing CSS leakage between the editor and the host application. It features a customizable Markdown parser that allows developers to replace the default parsing engine with custom functions to transform text into specific output formats. The system provides a split-pane inter

Simpl is an HTML, CSS, and JavaScript example library that provides a collection of minimal functional demonstrations of core web technologies and native browser APIs. It serves as a reference implementation and pattern gallery for frontend development, offering practical examples of how to implement common web features. The project showcases a wide range of browser capabilities, including real-time web communication via WebSockets and WebRTC, responsive web design techniques for adaptive layouts, and the implementation of offline workflows using service workers. It also provides demonstratio

React Redux is a global state management bridge and a set of bindings that connect React components to a Redux state store. It serves as a communication layer and state store connector, allowing a declarative user interface to synchronize with a centralized source of truth. The library enables the synchronization of shared global state across an application by providing mechanisms to read state and dispatch actions directly from the view layer. It ensures predictable state transitions by bridging the gap between UI components and the Redux state container. The project covers core capabilitie

Craft is a multiplayer voxel sandbox written in C. It utilizes an OpenGL voxel engine to render a block-based world and implements an infinite terrain generator that uses noise functions to create deterministic, procedural landscapes. The project features a networked environment where players can build and modify a shared world using socket-based state synchronization. To maintain consistency across sessions, it employs a voxel world database to store and retrieve modified block coordinates. The system covers a range of capabilities including 3D collision detection for character movement, to

This project is a collection of technical demonstrations and prototypes that showcase various HTML5 APIs, multimedia capabilities, and web standard implementations. It serves as a frontend technology sandbox and a gallery of implementation proofs-of-concept for modern browser features. The collection includes specialized showcases for HTML5 multimedia, featuring the manipulation of audio, video, and real-time media streams. It also provides a series of experiments focused on prototyping web capabilities to verify technical feasibility and browser support in live environments. The project cov

Nullboard is a local-first productivity tool and browser-based note organizer. It functions as a Kanban task board for tracking workflows and organizing tasks into draggable notes and lists within a minimalist interface. The project features a customizable Kanban UI that allows users to adjust visual preferences, including themes, font families, font sizes, and layout widths. The system manages data through local browser storage for offline access, supplemented by board file imports and exports and token-based remote synchronization for backups. It includes a revision-based undo system for

Murder is an entity component system game engine designed for 2D game development. It provides a core framework for managing game objects through an ECS architecture and includes a dedicated 2D game editor for asset management and real-time property configuration. The engine features a specialized 2D rendering pipeline supporting pixel art, sprite slicing, and parallax effects. It includes a hierarchical A* pathfinding system for agent navigation and a comprehensive asset management system for serializing and loading game resources. The project covers a broad range of capabilities, including

Immutable.js is a library of persistent data structures and a functional state management toolkit. It provides a collection of immutable objects and arrays that prevent direct mutation to ensure predictable state management in JavaScript applications. The library utilizes structural sharing to efficiently create new versions of data without full copying and implements lazy sequence processing to chain data transformations that execute only when values are requested. It also supports batch mutation processing, allowing multiple changes to be applied to a temporary mutable copy before returning

usehooks-ts is a comprehensive collection of reusable TypeScript-based hooks designed for managing state, DOM events, and browser API interactions within React applications. It provides a typed library of functions to handle common frontend patterns and side effects. The project distinguishes itself by offering specialized hooks for browser integration, including tools for interacting with the system clipboard, managing local and session storage persistence, and loading external scripts. It also includes utilities for responsive UI development, such as tracking media queries, window dimension

egret-core is a cross-platform game engine and mobile application framework used to develop 2D and 3D software for Android, iOS, and Windows. It serves as a multi-platform graphics engine and input handler designed to maintain consistent visual output and interaction behavior across different hardware. The project provides a game physics and animation suite that integrates external libraries for skeletal animations, particle systems, and complex physics simulations. It utilizes a hardware-abstraction layer to standardize touch, keyboard, and mouse interactions across multiple operating system

A framework for building Mobile cross-platform UI

Guava is a Java standard library extension and utility toolkit that provides optimized data structures, concurrency tools, and core extensions. It serves as a comprehensive set of helpers for Java development, focusing on reducing repetitive boilerplate logic. The project is distinguished by its specialized implementations of immutable collections, which ensure thread safety and data consistency by preventing accidental modification. It also includes a dedicated graph data structure library for modeling and traversing networks of interconnected nodes and edges, alongside advanced collection t

Collections is a JavaScript data structure library that provides unified interfaces for sets, maps, ordered sequences, and key-value storage. It includes capacity-bounded eviction mechanisms, categorical grouping, and set membership collections designed to organize and manage complex datasets through consistent traversal methods. The library offers advanced primitives such as circular ring buffers that automatically discard old entries upon reaching capacity limits, and comparator-driven sorted sequences maintained through binary search positioning. It supports persistent state snapshotting v

cocos2d-objc is an Objective-C 2D game engine designed for developing interactive games and applications. It serves as a cross-platform game framework that enables the deployment of a shared codebase across iOS, tvOS, and macOS. The project features a hardware-accelerated 2D renderer utilizing OpenGL and Metal to display sprites, tile maps, and particle effects. It includes a dedicated OpenAL audio engine for managing music and spatialized sound effects, alongside a cross-platform input handler for processing touch, mouse, keyboard, and accelerometer events. The framework provides capabiliti

Flux is an application architecture framework and client-side state orchestrator. It implements a unidirectional state management pattern to ensure data flows in one direction, preventing unpredictable state changes and maintaining consistency across the user interface. The system functions as an action-driven state architecture where changes are triggered by plain object actions. A centralized dispatcher routes these actions to multiple data stores, which partition the application state and notify views of changes via a publisher-subscriber synchronization pattern. This approach provides a

This is a persistent data structure library for JavaScript that provides collections which prevent the direct mutation of objects and arrays. It serves as an immutable state management tool and functional programming utility, ensuring that data remains unchanged after creation to simplify change detection and state tracking. The library enables the maintenance of application state by producing new versions of data structures during updates. It focuses on efficient data comparison by checking actual content instead of memory references and supports a functional programming workflow to prevent

Butterfly is an interactive graph visualization library and SVG-based diagramming engine used to build node-based workflow designers and visual flow editors. It provides a framework for rendering interconnected nodes, edges, and groups to model technical architectures, business processes, and data-driven workflows. The project is distinguished by its ability to integrate custom UI components as graph nodes and its specialized support for data lineage visualization. It enables the mapping of relationships between data fields, tables, and business entities to track provenance and monitor workfl

language-ext is a functional programming framework for C# that provides a suite of immutable data structures and monadic types. It enables the implementation of pure functional programming patterns, utilizing containers to manage side effects, optional values, and error handling. The library is distinguished by its advanced concurrency and state management tools, including a software transactional memory system and lock-free atomic references. It also provides specialized utilities for distributed systems, such as vector clocks for causality tracking and deterministic data conflict resolution

Functional-Light-JS is a JavaScript functional programming library designed to implement functional patterns within JavaScript applications. It serves as a toolkit for declarative data processing, immutable data management, and the construction of complex logic through higher-order functions. The library focuses on a pragmatic implementation of functional programming, providing utilities for curried argument application and function composition. It emphasizes the use of pure functions to calculate state updates and manage application data without side effects. The project covers broad capabi

Redux is a global state management library and predictable state container for JavaScript applications. It implements a store pattern that maintains the entire application state as a single source of truth, ensuring consistent behavior across different components and environments. The library relies on a unidirectional data flow where state updates follow a strict one-way cycle. This is achieved through a system of discrete actions, pure-function reducers, and a centralized store to ensure that state transitions remain predictable and traceable. The framework includes capabilities for monito

Zenpen is a browser-based text editor designed as a minimalist writing tool. It provides a distraction-free environment for composing and formatting plain text using Markdown syntax. The editor removes visual clutter and complex menus, replacing them with a streamlined interface to maintain creative flow. Formatting options for bold, italics, and hyperlinks are provided through a contextual menu that appears only when text is selected. Content is persisted locally using browser storage, allowing users to save their writing progress without requiring a remote account.