It's not easy to run an organization with 1,500 PCs on almost no Microsoft products, but that's what Mosaic, a faith-based nonprofit organization that provides services to the developmentally disabled, is doing with the help of open source and cloud computing.Mosaic began investigating client virtualization and desktop Linux in 2004 as a possible cost-cutting exercise, and slowly began repurposing its old PCs as thin clients running remote instances of Novell SUSE Linux. The Omaha-based organization switched from SUSE to Ubuntu last year and ramped up its project. Now, almost all of Mosaic's 1,500 PCs in more than a dozen locations run Ubuntu 9.04 delivered over its network with desktop virtualization from NoMachine. Those PCs also run OpenOffice as a productivity suite, Firefox as the Web browser, open source GIMP for photo editing, Scribus for desktop publishing, GLabels for printing labels, and e-mail from Google. On the server side, most of its Web applications run on Apache, and it uses OpenLDAP for directory services and access management. In all, Mosaic CIO Keith Courier estimates the company is saving $400,000 annually, on a total IT budget of about $2 million, by getting rid of most other proprietary software. The IT team also is three full-time employees smaller as a direct result of the move, partially because it no longer needs staff to manage Exchange servers. For apps that can't run on Linux, or that need Internet Explorer, Mosaic has a server that lets people log into and access Internet Explorer 6, or installs a full copy of Windows XP to run in a virtualized environment on the Linux desktop, since all those old PCs came with XP licenses. Only a few dozen people in the organization need XP, mostly for one billing application. Major companies aren't going to follow Mosaic's model, as most find the increased support and training costs and performance trade-offs outweigh any open source licensing savings. In fact, Microsoft's new Windows 7 operating system has a lot to interest CIOs (see story, "8 Things To Think About For Windows 7"). But at a time when the economy has driven CIOs to consider new software alternatives, it shows yet another possibility.