One assumption that is often made about desktop virtualization is that whatever is on the back end of the solution is going to be from the same vendor on the front end.

But it turns out that right now the most popular desktop virtualization combination is Citrix on the client and VMware on the server. Much of this has to do with the historic strengths of the two companies as both VMware and Citrix have had a limited amount of success ejecting each other from their core installed base of customers, many of which they appear to have in common with each other.

This situation is starting to attract the attention of vendors such as Virsto Software, a provider of storage systems that are optimized for virtual server environments. At the Interop 2012 conference this week the company announced the creation of a beta program for Citrix XenDesktop on vSphere. The idea is is integrate of Virsto’s storage hypervisor for virtual machines running on VMware with Citrix XenDesktop software.

According to Eric Burgener, vice president of product management for Virsto Software, there’s a lot of demand for this capability among virtual desktop infrastructure (VDI) customers that want to find a lower cost way to integrate Citrix desktop virtualization software with the VMware software they already have running on their servers. The Virsto software is designed to provide a way of accomplishing that goal without requiring customer’s to upgrade their storage infrastructure in order to provide the I/O performance required in VDI scenarios.

Burgener says that a lot of VDI projects never get past the pilot stage because of the infrastructure upgrade costs associated with VDI implementations. Solution providers can help customers get past that issue by making use of a software approach that improves storage throughput in virtual machines environments by a factor of 10, says Burgener.

The Virsto offering highlights the increasing diversity of the virtualization world. With Microsoft gaining ground it’s only a matter of time before we see greater usage of Citrix client software and Microsoft Hyper-V virtualization software. At the same time, customers in the future will be looking to integrate the desktop virtualization capabilities of Windows 8 with VMware and Citrix Xen virtual servers.

Not only will they need somebody to actually integrate those environments, they’ll also be looking for software to help them manage it. As the virtualization world becomes more diverse that should create any number of opportunities to sell virtual machine neutral management software. As long as customers continue to separate the management of desktop and servers even in a virtual world, there should be no end of opportunities for solution providers that can help customers mix and match virtualization offerings from multiple vendors.

But before any of that can happen, Burgener notes that customers need to make sure that VDI works in a way that they can afford. Most customers are going to resist server and storage upgrades, so the fastest way to get an VDI project into production is to show them a way that gets VDI to work without requiring customers to buy new servers and storage systems that many of them don’t have the budget to afford, at least not until they free up some money by getting VDI to actually work.