Snö is an awesome, free (gpl) program only available for Mac, that is part of the category Customize your Mac with subcategory Themes and Effects.
More about Snö
Since we added this program to our catalog in 2006, it has obtained 6,321 downloads, and last week it gained 4 downloads.The program version is 2006.12.8 and was updated on 12/14/2006. It's available for users with the operating system Mac OS X and former versions, and you can get it only in English. Snö is a slick software that will require less storage space than the average program in the section Customize your Mac. It's very heavily used in many countries such as Canada, United Arab Emirates, and Pakistan.