VMware and Red Hat on Wednesday said they plan to expand cooperation on the Linux virtualization front, a move that mirrors the interoperability pact unveiled by their respective rivals, Microsoft and Novell.

At VMworld in Los Angeles, VMware and Red Hat said they aim to develop a certification program and work together to achieve a high degree of interoperability between Red Hat Enterprise Linux 5 and VMware's virtualization platform. Red Hat's upcoming Enterprise Linux 5 will include the open-source Xen virtualization hypervisor.

VMware said it would offer support, certification and interoperability with Red Hat Enterprise Linux 5 and the Red Hat Application Stack. Red Hat Linux was the first operating system certified by VMware as part of its Virtual Appliance Marketplace, which was unveiled on Tuesday.

In addition, Red Hat and VMware plan to deliver joint solutions to the channel that bundle Red Hat Enterprise Linux 5 and the Red Hat Application Stack with VMware's Virtual Infrastructure and VMware Server. The two companies also said they will engage in an open-community development environment to create an interoperable virtualization model.

The Microsoft-Novell pact, announced last week, is a wide-ranging agreement that calls for better interoperability between Windows and SUSE Linux workloads on virtual platforms, as well as joint cooperation on business and legal fronts.