A normal diff between 2 text files enables you to quickly determine 2 things – Whether the two input files are identical, and if not, exactly where the differences lie.

A Perceptual Diff (pdiff) allows you to do the same with 2 image files and quickly identify whether the two images are identical, and highlight areas where the 2 images mismatch. pdiffy does exactly this.

via kennychua/pdiffy.


A library for using ClojureScript’s persistent data structures and supporting API from the comfort of vanilla JavaScript. […]

  • Efficient immutable data structures – no cloning required
  • Uniform iteration for all types
  • Value based equality



Wu.js is a library for lazy, functional programming in Javascript. Works great in the browser, and also with CommonJS (including node and Narwhal).

The largest part of wu is dedicated to iterators. Iterators are lazy sequences with a number of methods that encourage functional programming.

via wu.js.


Underscore is a utility-belt library for JavaScript that provides a lot of the functional programming support that you would expect in Prototype.js (or Ruby), but without extending any of the built-in JavaScript objects. [..] Underscore provides 80-odd functions that support both the usual functional suspects: map, select, invoke — as well as more specialized helpers: function binding, javascript templating, deep equality testing, and so on. It delegates to built-in functions, if present, so modern browsers will use the native implementations of forEach, map, reduce, filter, every, some and indexOf.