All you need to do is upload the plugin folder to your plugin directory and activate to see falling snow on your blog.
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3.0 [January 30, 2011] Updated snow fall script and generally cleaned things up. 2.0 [November 07, 2009] Updated snow fall script and generally cleaned things up. 1.3 [December 27, 2007] Changed z-index of snow so it's on top of everything. 1.2 [December 26, 2007] snowCollect now working, thanks to Scott Schiller for his help. 1.1 Added additional style declarations for themes that style the img tag. 1.0 [December 25, 2007] First version