Rubin: Be sure to try the 1.0.0 that was released today.

Why no Airfoil for Linux
Simply put, because there's approximately zero market for paid software on Linux. We're a software company (not a support company, not a documentation company, etc.), we sell software. Porting Airfoil Speakers to Linux was made easier thanks to Mono, so we decided to give it a go, as it adds value to Airfoil for Mac and Windows. Airfoil itself, however, for Linux, just doesn't make sense for us. Sorry!