"RAR files are a popular compression format, and this free extractor offers reliable service."
http://download.cnet.com/Free-RAR-Extract-Frog/3000-2250_4-10804840.html (http://download.cnet.com/Free-RAR-Extract-Frog/3000-2250_4-10804840.html)
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Had to jump through a few hoops to get The Essential Guide to Framing PDF downloaded and extracted but it is a good manual. Lots of helpful diagrams and data.
7zip is another great program. I wouldn't use any other.