Open-source alternatives to Immer

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

Zustand is a state management library that provides a centralized store for managing shared application data. It functions as a reactive container that connects application state to components, allowing them to subscribe to specific slices of data and trigger updates automatically. By utilizing selector-based data access and immutable state updates, the library ensures that components only re-render when their observed data changes, maintaining a predictable and efficient data flow. The library distinguishes itself through a pluggable, middleware-based architecture that allows for the extensi

use-immer is a React hook library that provides an immutable state hook for updating complex state objects. It integrates Immer state management into the React component lifecycle, allowing developers to handle state transitions by modifying a draft object rather than manually copying state. The library enables the update of deeply nested data structures without the use of spread operators to copy every level of the state tree. It uses a mutation-based draft approach to ensure that the original state remains untouched while producing a new immutable version of the data. The project covers ge

re-frame is a functional framework for building single-page applications in ClojureScript. It provides a centralized, immutable database that serves as the single source of truth for the entire application state, enforcing a strict unidirectional data flow where events trigger state transitions and subsequent view updates. The framework distinguishes itself through a reactive signal graph and an interceptor-based middleware pipeline. By treating application logic as a sequence of data-driven events and declarative side effects, it decouples business logic from the view layer. This architectur

Redux is a predictable state container designed to manage global application data through a centralized store. It operates on a unidirectional data flow architecture where state transitions are triggered by dispatching action objects, which are then processed by pure reducer functions to produce a new, immutable state tree. This approach ensures that application data remains consistent and traceable across the entire component hierarchy. The library distinguishes itself through a functional pattern that relies on pure functions for state logic and a middleware-based extension system. This mid

This is a JavaScript immutable data library used to create objects and arrays that prevent direct mutation. It serves as an immutable state manager and object wrapper designed to ensure data consistency by blocking modifications while remaining compatible with standard JavaScript syntax. The library functions as a converter that transforms standard mutable data into frozen structures and can convert them back for local modifications. This allows for a workflow where data is switched between immutable and mutable versions to perform bulk edits before locking the state again. The project provi

Draft-js is a framework for building customizable rich text editors within React applications. It serves as a state manager for document content and metadata, providing a system to handle text ranges, atomic blocks, and the conversion of HTML strings into structured document formats. The framework enables the creation of interactive editing interfaces that support custom inline styling and configurable block rendering. It includes tools for managing rich media document handling, allowing the integration of non-editable content and metadata into a text stream. The project covers a broad range

Swift Algorithms is a library of sequence and collection algorithms for Swift, providing operations for splitting, cycling, combining, and sampling collections with lazy evaluation. It extends Swift's standard library with algorithms that work across all types conforming to Sequence and Collection protocols, enabling efficient data processing without intermediate storage. The library specializes in combinatorial enumeration, generating all possible permutations, combinations, and product sequences from collections for testing and exploration. It also includes utilities for splitting collectio

AlgoXY is a functional programming educational book and technical publication produced as a LaTeX digital book. It serves as a programming education resource and library focused on functional algorithms and data structures. The project provides a collection of persistent data structures, such as trees and heaps, designed for immutable state management. It includes a series of implementation exercises and verified answers to teach core computer science concepts through the practical application of functional logic. The content covers the design of persistent data structures and the implementa

Unstated is a React state management library that encapsulates application state and update logic within decoupled containers. It functions as a container-based state store, allowing state and business logic to be organized into standalone classes that trigger component re-renders when data changes. The project serves as a dependency injection framework, enabling specific state container instances to be supplied to the component tree. This mechanism supports the use of mock containers or stubs to facilitate controlled testing and custom configurations. The library covers global state managem

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

React is a JavaScript library for building user interfaces based on a component-driven architecture and unidirectional data flow.

This is a browser-based Tetris game built with React, using Redux and Immutable.js to manage all game state in a single immutable store. The application renders the game board, next-block preview, and score display as React components, with state transitions that are predictable and support time-travel debugging through the Redux DevTools Extension. The game distinguishes itself through several integrated capabilities. It automatically adapts between keyboard and touch controls based on the user's input device, with configurable repeat rates for responsive gameplay. A persistence layer serial

Lodash is a JavaScript utility library and data manipulation toolkit. It provides a collection of modular functions for transforming, filtering, and validating arrays, objects, strings, and numbers. The project functions as a functional programming toolkit, offering capabilities for function composition, currying, and lazy evaluation. It includes mechanisms for execution control, such as debouncing and throttling, to manage the timing and frequency of function invocations. The library covers a broad surface of data operations, including deep cloning and merging of complex nested structures,

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

Just is a collection of JavaScript utility libraries designed for data manipulation, functional programming, performance optimization, statistical analysis, and string processing. It provides a set of tools for deep cloning, filtering, and transforming complex objects and arrays. The project is structured as a series of zero-dependency modules, allowing utilities to be used independently to minimize bundle size. It implements functional programming patterns including currying, piping, and partial application, and provides execution control through memoization, debouncing, and throttling. The

Valtio is a proxy-based state management library and reactive state engine that provides a mutable state store. It allows application state to be updated through direct object mutations rather than immutable patterns, using JavaScript proxies to track changes and trigger updates. For React applications, it includes a synchronization hook that ensures components re-render only when the specific properties they access are modified. The system supports reactive data derivation through computed properties that automatically update when their underlying dependencies change. It maintains reactivity

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

pypdf is a Python library for parsing, manipulating, and generating PDF documents. It provides high-level operations for document processing, such as merging multiple files into one or splitting a single document into smaller files. The project includes specialized tools for managing interactive elements, including the creation and modification of annotations, hyperlinks, and form fields. It also supports advanced metadata management, allowing for the extraction and modification of standard document properties and XML-based XMP metadata. Beyond basic structural changes, the library covers pa

DeepCopy is a recursive object cloning library designed to create independent copies of complex nested objects. It functions as a state snapshot utility and object cloning tool that produces clones while preserving the original object graph. The library includes a circular reference handler to duplicate data structures containing self-referencing loops without causing infinite recursion. It also serves as an object property transformer, allowing for the filtering or modification of specific fields and types during the cloning process based on custom matching criteria.

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

Jotai is a state management library for React applications that utilizes an atomic model to handle data. It organizes application state into small, independent units called atoms, which automatically track dependencies and trigger granular updates to components. By building state through these composable primitives, the library ensures that only the necessary parts of an application re-render when data changes. The library distinguishes itself through its flexible approach to state composition and asynchronous data handling. It integrates promises directly into the state model, allowing devel

Iced is a cross-platform graphical user interface framework designed for building interactive applications with a focus on type safety and predictable state management. It utilizes a declarative architecture that separates application state, update logic, and view rendering, allowing developers to construct complex interfaces by nesting reusable functional components. The framework distinguishes itself through an Elm-inspired message-passing pattern, where all user interactions are processed as discrete messages to ensure reliable state transitions. It employs an immediate-mode rendering para

Pinia is a state management library for Vue applications that provides a centralized, type-safe architecture for organizing reactive data. It utilizes a modular store pattern, allowing developers to define independent, reusable state containers that manage shared application data, computed getters, and executable actions. The library distinguishes itself through a flexible definition model that supports both functional setup patterns and traditional object-based structures. It features a plugin-based extension architecture that enables developers to hook into the store lifecycle for custom fu

React is a JavaScript library for building user interfaces through the composition of modular, self-contained components. It employs a declarative programming model where developers describe the desired visual state, and the library automatically manages the underlying document updates and state synchronization. By utilizing a virtual representation of the document, it calculates and applies minimal changes to the browser, ensuring efficient rendering even in complex applications. The library distinguishes itself through a sophisticated scheduling system that manages rendering work in increme

Fury is a multi-language binary serialization framework designed for encoding domain objects and complex graphs to facilitate cross-language data exchange. It includes an interface definition language compiler that translates schema definitions into idiomatic native types and serialization boilerplate across multiple languages. The project distinguishes itself through a zero-copy binary reader that allows specific fields to be accessed without deserializing the entire object, as well as an object graph serializer that preserves circular references and referential integrity. It also features a

MPX is a cross-platform framework designed to build applications for multiple mini-program ecosystems and the web from a single codebase. It utilizes a static transpilation pipeline to transform source code into platform-specific bundles, employing a single-file component system that encapsulates templates, logic, and styles. The framework provides a reactive state management system that automatically synchronizes application data with the user interface through computed properties and watchers. The project distinguishes itself through a robust build-time toolchain that supports sub-package p