kwin-style-crystal 2.2.1-2ubuntu2 (ppc64el binary) in ubuntu utopic

 Crystal is a pretty simple and clean theme, which also provides pseudo
 transparent title bar, buttons and borders, and round corners as well.
 Transparency and buttons can be customized to match your wishes.
 .
 And it is of course nice to look at. Upstream says:
 "- Don't forget to breathe, while drooling."