Windows Vista debuted to muffled applause, followed by lackluster sales. Up until June 30, cash-strapped businesses looking to avoid the cost of upgrading to new Vista-compatible hardware could still purchase trusty Windows XP. Now, however, Windows XP is available only as a costly "downgrade" from Windows Vista--if you buy a copy of Vista, you can install the 6-year-old XP operating system using the Vista license.

If that feels like a waste of your small business's precious IT budget, and you're still looking for an alternative to Windows Vista, look no further than Linux. The latest distributions are free, easy to install, and highly customizable; they harness your existing hardware without overtaxing it; and they include a wealth of productivity applications and utilities. You may already have a closet Linux expert on staff, but if you don't, paid support is usually available at rates far less than Microsoft's.

Making the switch from Windows to Linux will incur some costs as employees and support staff adjust to the new system's configuration settings, utilities, and applications. Even so, the savings in future hardware and software upgrades could be huge.

No License, No Fee, No Problem

Though you can purchase boxed commercial versions of Linux that include support, every Linux distribution is also available for free under the terms of the open-source Gnu General Public License, or GPL. Once you figure out which distribution you'd like to use (see below), you can simply download, burn, and install it on as many systems as you choose. Your software licensing fee is zero, compared with the $300 per seat for the full version of Windows Vista Business Edition. And, another bonus, Linux lacks Microsoft's intrusive activation requirements.

In addition to thousands of other free applications (see "Linux Replacements for Your Favorite Windows Apps" for some of my favorites), most Linux distributions come with a copy of OpenOffice.org. Though not a feature-for-feature substitute for Microsoft Office, OpenOffice.org definitely does the job, and for $500 less per workstation than the cost of Office Professional 2007. OpenOffice.org lacks an equivalent to Microsoft Outlook, but just about every Linux distribution includes Novell's free Evolution PIM.

A few key Windows-based applications such as AutoCAD and Photoshop lack Linux replacements, but for many office workers the missing functionality hardly merits spending $800 more for Windows and Office. Many Windows applications will run at native speed under Linux via the Wine utility included with most distributions. For those that don't work with Wine, two more options exist: You can install a copy of Windows using one of the available free virtualization utilities, such as KVM (Kernel-based Virtual Machine, built into the Linux kernel) or VMWare Server, or you can install Linux to dual-boot with Windows.

For most distributions, the same disc will contain server applications, including the Apache Web Server, the MySQL database engine, virtualization, and support for leading commercial databases and CRM applications from companies like Oracle, Sybase, and SAP. The Samba networking software emulates Windows Server's networking features admirably, and for free, versus Windows Server 2008's starting price of $999. You can even replace your costly Exchange server installation with the free, open-source Zimbra Collaboration Suite.

Whether you're using desktop or server versions of Linux, the operating system is famous for one other important feature that Microsoft is still gradually adding to Windows: security. Linux is not somehow magically immune to viruses, worms, and other Internet-based attacks. However, the reality is that the vast majority of existing attacks target Windows and Windows applications. Mostly by design, Linux is simply not subject to most of the Internet-based malware that threatens PCs. The overwhelming majority of malware targets Windows.