This is an sgi variation GTK+ theme. I love the classic IRIX style. But the strong embossed widgets now look a bit out of date. I developed this theme and tried to make it look more smooth and elegant, but to keep the essence of the original sgi grey scheme.
It is light and minimal. There's no transition or effect, and also no need for any extra theme engine. Just keep everything clear and efficient.
To install the theme, unzip the archive and copy the theme in your theme directory (~/.themes/).
This is a [GPL 3 https://www.gnu.org/licenses/gpl.txt] free software. Feel free to change and share the code.