One of the harder Google and Bing searches is to find out whether DB2 for Linux, UNIX, and Windows (DB2 LUW) is supported on a Linux system running on the mainframe (System z). Often only references to DB2 for z/OS or DB2 on Linux are found. Anyway, to answer a question that I got,
DB2 for Linux is supported on the so-called zLinux and it might come to a surprise that you can choose between DB2 for z/OS (with a deep system integration) or DB2 for the distributed platform.