Full web stack No browser required PhantomJS is a headless WebKit scriptable with a JavaScript API. It has fast andnative support for various web standards: DOM handling, CSS selector, JSON, Canvas, and SVG.
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.