http://ostatic.com/blog/vmware-saw-the-threat-releases-open-source-virtualization-client

"The CEO replacement who entered VMware last year was Paul Maritz, a long-time Microsoft executive with intimate familiarity with how Windows swallowed up entire categories of utility software as it grew up by simply wrapping free utilities into the operating system. Paul knows about that, and he had to have seen last year the dual threats to VMware of open source virtualization offerings and virtualization on board in operating systems. The VMware View Open Client allows businesses to host virtualized desktops in the data center, and users can access their desktops from any device. Going with an open source solution like this was VMware's only choice, especially as Microsoft includes Hyper-V virtualization in Windows Server. I'm sure Maritz was very focused on the Microsoft threat, because he used to be behind similar threats. VMware can grab market share with this move, stave off Microsoft's dominance, and offer support and services around its open source offering.'"