Amazon.com just published my 4 star review of Linux on the Mainframe. From the review:
"Server consolidation" is the latest buzzword for downsized IT staffs. Many believe this means reducing the number of Windows servers running on Intel hardware. "Linux on the Mainframe," (LOTM) written by experts from IBM, offer an alternative: virtualization on the IBM zSeries and S/390 mainframes. Virtualization is the process of running dozens or hundreds of operating system "images," each of which thinks it is running on dedicated hardware. LOTM explains the improvements in reliability, availability, and serviceability from implementing this sort of system.