Citrix Monday unveiled a software application and a plan to give network administrators a consistent way to create and administer different virtual desktops for end users.

The idea is to transplant the client Windows operating systems from individual PCs to a trinity of centrally managed, scalable server options, including Windows Terminal Services, various commercial and open source virtual machine servers, and rack-mounted blade PCs. Then, Citrix's new software will coordinate and administer users' access, via any Windows client device, to these remote desktops.

Citrix is one of many vendors extending virtualization to desktop operating systems and applications. Rivals include Altiris and Propero, and even VMware and XenSource, which are nevertheless listed as partnering with Citrix on this new plan.

Desktop virtualization is a way to dramatically simplify end user computing by consolidating scores or hundreds of desktop operating system and applications on servers, and then letting users access these via a thin client instead of a full-blown PC.

The first step by Citrix, unveiled this week at the company's annual iForum customer conference, is the Desktop Broker, a software program that plugs into the company's flagship Presentation Server 4.0. Administrators identify the relevant backend servers, including specific Windows Terminal Services boxes, virtual machine (VM) servers, or blade PCs, all of which can run instances of Windows XP.

A sales rep, for example, connects and authenticates via Presentation Server as usual. But Desktop Broker in effect intercepts this connection and redirects it through Presentation Server to the appropriate backend, in this case a dedicated virtual machine for the sales department, running on VMware's virtual server, for example. Without Desktop Broker, the sales rep would have to separately and manually log into each separate virtual machine for different applications, says Nabeel Youakim, vice president and product line executive for Citrix Presentation Server.

Desktop Broker will also be able to shift users to VMs that have less of a load, optimizing performance.

Citrix's larger plan is to copy some of the desktop virtualization components in Presentation Server and write new code to create a standalone application that won't need Presentation Server. This new server application will let enterprises virtualize their desktop operating systems, running this software on any combination of Windows Terminal Services, VM servers, or blade PCs. This trio of options gives the project its code-name: Project Trinity.