When I send a win rar file, does the recipient need to have win rar as well or does win zip open it?

If the receiver of your *.rar file does in fact have WinZip (WinZip® - The Zip File Utility for Windows - Zip/Unzip, Encrypt/Decrypt) then the answer is YES. They cannot, however, create .rar files. Another option is ZipGenius (ZipGenius.it - Free zip utility for Windows that handles zip, rar, cab, 7-zip archives and CD-ROM ISO9660 image files) that opens and compresses many file types. Unlike WinZip, it is free.