JavaScript Functional

Open-source JavaScript projects categorized as Functional

Top 12 JavaScript Functional Projects

  1. fantasy-land

    Specification for interoperability of common algebraic structures in JavaScript

    Project mention: JavaScript's Missed Opportunity: Async/Await, Optional Chaining, and flatMap are the same thing | dev.to | 2025-02-19

    (This was one of the purposes of the Fantasy Land specification, to define common interfaces for generalized operations that could benefit from language-syntax-support.)

  2. SurveyJS

    JavaScript Form Builder with No-Code UI & Built-In JSON Schema Editor. Keep full control over the data you collect and tailor the form builder’s entire look and feel to your users’ needs. SurveyJS works with React, Angular, Vue 3, and is compatible with any backend or auth system. Learn more.

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  3. folktale

    [not actively maintained!] A standard library for functional programming in JavaScript

  4. Rambda

    Typescript focused FP library similar to Remeda and Ramda

  5. bitECS

    Flexible, minimal, data-oriented ECS library for Typescript

  6. partial.lenses

    Partial lenses is a comprehensive, high-performance optics library for JavaScript

    Project mention: Show HN: JAQT – JavaScript Queries and Transformations | news.ycombinator.com | 2024-09-16

    For the same purpouse I ofter use this https://github.com/calmm-js/partial.lenses

  7. pampy.js

    Pampy.js: Pattern Matching for JavaScript

  8. puresql

    ES6/7 ready SQL library for node.js inspired by Clojure's yesql

  9. InfluxDB

    InfluxDB – Built for High-Performance Time Series Workloads. InfluxDB 3 OSS is now GA. Transform, enrich, and act on time series data directly in the database. Automate critical tasks and eliminate the need to move data externally. Download now.

    InfluxDB logo
  10. eth-fun

    A functional and state-less library for the Ethereum JSON-RPC.

  11. kesh

    A simple little programming language that could one day compile to JavaScript

  12. declarative-merge

    Merge objects/arrays declaratively

  13. openinf-util-text

    Cross-platform terminal-friendly text utilities

  14. noLoopFor

    JavaScript library for making functional loops

NOTE: The open source projects on this list are ordered by number of github stars. The number of mentions indicates repo mentiontions in the last 12 Months or since we started tracking (Dec 2020).

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JavaScript Functional related posts

  • JavaScript's Missed Opportunity: Async/Await, Optional Chaining, and flatMap are the same thing

    1 project | dev.to | 19 Feb 2025
  • Have any of you designed a conlang, and then designed a programming language based on the conlang or any fictional culture that would use it?

    2 projects | /r/ProgrammingLanguages | 30 Mar 2023
  • Too many words about Rust's function syntax

    1 project | /r/ProgrammingLanguages | 28 Jan 2023
  • Ask HN: Tools you have built for yourself?

    17 projects | news.ycombinator.com | 23 Jan 2023
  • How elaborate could/should a transducers combiner function be?

    2 projects | /r/functionalprogramming | 5 Jan 2023
  • General Functional Programming Resources

    3 projects | /r/functionalprogramming | 17 Dec 2022
  • Updates from the 93rd TC39 meeting

    2 projects | /r/javascript | 3 Dec 2022
  • A note from our sponsor - SurveyJS
    surveyjs.io | 20 Jul 2025
    Keep full control over the data you collect and tailor the form builder’s entire look and feel to your users’ needs. SurveyJS works with React, Angular, Vue 3, and is compatible with any backend or auth system. Learn more. Learn more →

Index

What are some of the best open-source Functional projects in JavaScript? This list will help you:

# Project Stars
1 fantasy-land 10,202
2 folktale 2,043
3 Rambda 1,731
4 bitECS 1,077
5 partial.lenses 921
6 pampy.js 552
7 puresql 51
8 eth-fun 29
9 kesh 22
10 declarative-merge 6
11 openinf-util-text 4
12 noLoopFor 3

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