Very nice.

Windows:

http://www.howtogeek.com/102261/how-to-run-internet-explorer-7-8-and-9-at-the-same-time-using-virtual-machines/

http://osxdaily.com/2011/09/04/internet-explorer-for-mac-ie7-ie8-ie-9-free/

• Download Virtual Box ) http://download.virtualbox.org/virtualbox/4.1.2/VirtualBox-4.1.2-73507-OSX.dmg
• ALL 7,8,9 Open Terminal and type :
  curl -s https://raw.github.com/xdissent/ievms/master/ievms.sh | bash