You may want to add our tool, Eggplant, to the list. It's one of the very few commercial tools available for GUI testing of any Linux application, and can also test Unix, Windows, or Mac applications with a single license. XRunner is no longer supported, so I suggest you take a look at Eggplant (the link is in my signature).
Doug Simons, Principal Developer
TestPlant, makers of eggPlant, the Cross-Platform GUI Testing Tool http://www.testplant.com