Red Hat said Wednesday that its KVM hypervisor, its pet virtualization scheme, can talk to Microsoft's Windows Server and that customers can now deploy jointly supported server virtualization environments that combine Windows Server and Red Hat Enterprise Linux (RHEL). The two companies have done the tests and validated the widgetry.

In February, when Red Hat started mapping out its intentions to major on KVM, the two companies agreed to validate and support each other's virtualization and operating system platforms.

So now RHEL 5.4 and the Kernel-based Virtual Machine (KVM) hypervisor can entertain Windows Server 2003, 2008 and 2008 R2 guests and Windows Server 2008 Hyper-V, Hyper-V Server 2008, Windows Server 2008 R2 Hyper-V and Hyper-V Server 2008 R2 can host RHEL 5.2, 5.3 and 5.4 guests.

RHEL 5.4, the latest cut of the Red Hat distribution, includes both Xen and for the first time KVM, but Red Hat's heart belongs to the open source KVM, which is supposed to be snazzier because it's part of the Linux kernel. Anyway, Red Hat bought Qumranet, the outfit behind the project, for $107 million cash a year ago and that means it can control KVM's destiny.

Red Hat also said Wednesday that Microsoft products certified on Windows Server and Red Hat products certified on RHEL are also supported in heterogeneous virtualized environments to give customers more deployment choice and flexibility.

As part of the kernel, Red Hat could already guarantee that the 3,000 applications certified for RHEL work on top the KVM hypervisor with no changes necessary.

Red Hat quotes Enterprise Management Associates principle analyst Steve Brasen explaining, "Often environment failures are not owned by any one specific support team despite established contracts and SLAs. With this announcement, Red Hat and Microsoft are ensuring their customers can resolve any issues related to Microsoft Windows on Red Hat Enterprise Virtualization, and Red Hat Enterprise Linux operating on Microsoft Hyper-V, regardless of whether the problem is related to the operating system or the virtualization implementation."