Though it is known that BizTalk Server 2006 was supported on Virtual Server 2005 . There was a silence on its support for othe VM's . It is quite hard to get some good documentation on what is Microsoft's stand on other VM's . This KB I recently saw throws more light
As per latest documentation (June 7 , 2007 ) BizTalk 2004 and 2006 is supported on Virtual Server and from a guarded silence on VMWARE now it has been clarified as commercially reasonable support . Which means as long as the issue on the virtual platform does not require a code fix as such, Microsoft would support it .
If the issue is on say VMware, and if it can be reproduced on a non VM box Microsoft would support it. I have heard from fellow MVP's that some customers have already gone and deployed BizTalk solution on VMWare as Vmware was consistent with their overall IT virtualization strategy that included non-ms applications and superior features for eg. Until Virtual Server 2007 ther was not 64 bit support which VMWare already had.
Also there does not seem any case study on customers going live on the BIZTALk + Virtualk Server platform that I have been able to find.
The full text of the KB is reproduced below
Microsoft BizTalk Server 2006 and BizTalk Server 2004 are fully supported when they are installed on a supported operating system that is running on Microsoft Virtual Server 2005. Neither BizTalk Server 2006 nor BizTalk Server 2004 may perform as expected if you have installed it on a supported operating system that is running on a virtual machine (VM) other than Virtual Server 2005. BizTalk Server 2006 and BizTalk Server 2004 have not been tested on operating systems that are running on VMs other than Virtual Server 2005.
Product support for BizTalk Server 2006 and for BizTalk Server 2004 on a VM other than Virtual Server 2005 is provided as commercially reasonable support. Commercially reasonable support is defined as all reasonable support efforts by Microsoft Customer Support Services that do not require BizTalk Server 2006 or BizTalk Server 2004 code fixes.
If you experience a problem in BizTalk Server 2006 or in BizTalk Server 2004 on a VM other than Virtual Server 2005, and the problem cannot be resolved through commercially reasonable support, the problem must be reproducible in a non-VM environment or on Virtual Server 2005 for the problem to be escalated to the BizTalk Server Product group as a bug.
If you are planning a Virtual Biztalk Installtion . Do drop me a line , I am very much interested