Based on Opus3 by systemx:
Original theme by b0se: http://b0se.deviantart.com
Opus3 is a simple, business-like theme for Xfce4. It uses GTK2 colours, so you can use it with any GTK2 theme and it will look just as good.
The IcoMax modification by Ben Klein provides more functionality and the option to show or hide any of the buttons supported by Xfce 4.2.