The battle to become the leading cloud computing vendor turned nasty yesterday after software giant Microsoft warned VMware customers about the dangers of being 'locked into' VMware's virtualisation technology.
The warning made in a letter published as a full-page advertisement in USAToday, and undersigned by management and security VP Brad Anderson, was published yesterday morning to coincide with the opening of VMware's VMworld conference in San Francisco.
"VMware is asking many of you to sign three-year license agreements for your virtualisation projects," reads Anderson's letter.
"[However,] signing up for a three-year virtualisation commitment may lock you into a contract with a vendor that cannot provide you with the breadth of technology, flexibility or scale that you'll need to build a complete cloud computing environment," it continued.
Anderson added: "If you're evaluating a new licensing agreement with VMware, talk to us first. You'll have nothing to lose and plenty to gain."
Although VMWare chief executive Paul Maritz didn't mention Microsoft's ad in his keynote address at VMworld, he did seem to be attacking Microsoft when he said that operating systems were becoming less important.
Commenting on the changing role of the operating system in cloud computing, Maritz said: "The traditional operating system (OS) has two functions, one to orchestrate the hardware, and the other to provide abstracted services to applications."
However, he argued that within a cloud environment, hardware orchestration was being carried out by the virtualisation layer while the application service provision would be carried out by some of the new frameworks and programming languages needed to code applications in the cloud.
"While the OS is not going to disappear, it'll become just one of several components that will fit into the broader view," said Maritz.
When discussing the new frameworks and programming languages that can be used in the cloud, Maritz mentioned VMware's own Spring technology and Ruby on Rails, but neglected to mention Microsoft's .NET framework.
Also at the event, VMware announced that the previously named Project Redwood, VMware's automation and management tool package for integrating private and public cloud environments, would be called vCloud Director.
VMware also launched three vShield security packages aimed at private or hybrid cloud computing platforms.
VShield App protects against network-based security threats, vShield Edge virtualises edge services like firewalls and load balancers, and vShield Endpoint offloads anti-malware services to dedicated virtual machines.
Microsoft chief executive Steve Ballmer said he was betting Microsoft on cloud computing, in an address delivered earlier this year at the University of Washington.