Once upon a time, VMware and Oracle were great business partners. VMware probably spent a great amount of resources in fine tuning its hypervisor for a smooth execution of Oracle products, and it certainly spent a huge effort in educating the customers about the viability of such virtualized solution.
In mid 2006 Oracle publicly declared its frustration for the lack of standardization in the virtualization market. It eventually decided to enter the hardware virtualization market itself, and launched the Oracle VM virtual infrastructure just one year later. As the company immediately restricted support to its own hypervisor only, the partnership with VMware ended.
The acquisition of Sun and Virtual Iron virtualization technologies suggested that Oracle would never change its mind about the topic, using restricted support as a tool to gain market share.
Meanwhile, VMware continued, for years, to recommend Oracle products on ESX and Oracle’s competitor SAP has been more than happy to highlight its broad support for market hypervisors.