Immutable.js vs Modernizr: What are the differences?

Developers describe Immutable.js as "Immutable persistent data collections for Javascript which increase efficiency and simplicity, by Facebook". Immutable provides Persistent Immutable List, Stack, Map, OrderedMap, Set, OrderedSet and Record. They are highly efficient on modern JavaScript VMs by using structural sharing via hash maps tries and vector tries as popularized by Clojure and Scala, minimizing the need to copy or cache data. On the other hand, Modernizr is detailed as "Respond to your user’s browser features". It’s a collection of superfast tests or detects as we like to call them which run as your web page loads, then you can use the results to tailor the experience to the user. It tells you what HTML, CSS and JavaScript features the user’s browser has to offer.

Immutable.js and Modernizr are primarily classified as "Javascript Utilities & Libraries" and "JavaScript Compilers" tools respectively.

Immutable.js and Modernizr are both open source tools. It seems that Immutable.js with 28K GitHub stars and 1.62K forks on GitHub has more adoption than Modernizr with 23.8K GitHub stars and 3.04K GitHub forks.

Instagram, Rove.me, and Broadly are some of the popular companies that use Immutable.js, whereas Modernizr is used by OneWire, GlobeBetting, and Actimore. Immutable.js has a broader approval, being mentioned in 30 company stacks & 63 developers stacks; compared to Modernizr, which is listed in 28 company stacks and 11 developer stacks.