lodash - Utility library delivering consistency, customization, performance, & extras. A better and faster Underscore.js.
immutable - Immutable data collections.
mori - Library for using ClojureScript’s persistent data structures and supporting API from the comfort of vanilla JavaScript.
Ramda - Utility library with a focus on flexible functional composition enabled by automatic currying and reversed argument order. Avoids mutating data.
Folktale - Suite of libraries for generic functional programming in JavaScript that allows you to write elegant, modular applications with fewer bugs, and more reuse.
underscore-contrib - The brass buckles on Underscore’s utility belt.
Mout - Utility library with the biggest difference between other existing solutions is that you can choose to load only the modules/functions that you need, no extra overhead.
Bacon.js - Functional reactive programming.
RxJS - Functional reactive library for transforming, composing, and querying v