highslide-software/highcharts.com — pull request #2354 by anutron (2013-10-11 18:17:33+00:00)
Title: Using document.id in mootools adapter instead of the more volitile $.

Mootools several years back deprecated the use of `$` in favor of document.id to avoid possible collisions with other libraries.

http://mootools.net/blog/2009/06/22/the-dollar-safe-mode/