i worked on .net before it was .net. we didn't have a name for the runtime, we (a very large we) just forked the J++ compiler and started hacking, calling the J++ language "COOL", for Common Object Oriented Language. For a long time the runtime was only usable by building executable files with the "jvc" compiler but compiled C#. We started a VB fork that compiled to the "clr". Yet still no name. At the end of the day it was purely a marketing decision.