jQuery 2.1.0, HTML, CSS, JavaScript
jQuery 1.11.0, HTML, CSS, JavaScript
No-Library (pure JS), HTML, CSS, JavaScript
IE 10+
Mootools 1.4.5, HTML, CSS, JavaScript
jQuery plugin that takes a collection of (presumed) floats, and applies a given class-name to each item that is left-most, or right-most in the content-flow
jQuery 1.9.1, HTML, CSS, JavaScript
Testing |= for various class-names