Enterprise-grade JavaScript snow effect for the internets, setting CPUs on fire worldwide every winter since 2003.
JavaScript CSS

README

/**
 * DHTML Snowstorm! JavaScript-based Snow for web pages
 * --------------------------------------------------------
 * Version 1.44.20131208 (Previous rev: 1.43.2011125)
 * Copyright (c) 2007, Scott Schiller. All rights reserved.
 * Code provided under the BSD License:
 * http://schillmania.com/projects/snowstorm/license.txt
 */

Homepage, demo, downloads etc.:
http://www.schillmania.com/projects/snowstorm/