Ubuntu Linux has been deemed one of PC World's Best Products of the Year for two years running. Why? It's completely free, it installs easily from one downloadable CD, and it focuses on user-friendliness. Since Ubuntu releases come twice each year, changes tend to be evolutionary. Ubuntu Linux 7.04 (nicknamed "Feisty Fawn") has a few major new features, and distinguishes itself mainly with its continued focus on usability, especially for newcomers to Linux.

The installation CD boots not to a setup program but to a fully functioning Ubuntu environment. This is your chance to kick the tires, to make sure audio, video, and networking are A-OK, to check to see if your peripherals are recognized, and so forth. To put Ubuntu on your hard drive, you need to double-click the Install icon on the desktop. Ubuntu Linux shrinks your Windows partition, making room for itself.

A migration assistant scours that partition, rounding up your browser settings and bookmarks, your document, music, and image files, and even your wallpaper files, copying everything over to the new Linux partition. The most vexing questions you'll be asked have to do with the language you speak and the time zone you reside in. After rebooting your PC, you select Ubuntu from your new boot menu, and shortly you're greeted by the user-friendly Gnome desktop. OpenOffice.org 2.2 is on hand and waiting, as are the Firefox Web browser, the Evolution e-mail client (a worthy Outlook imitator), the F-Spot photo manager (think iPhoto for Linux), the GIMP image editor, and Rhythmbox, Gnome's answer to iTunes and the Windows Media Player. Other available Linux distributions don't offer such a wealth of software. An experimental "Desktop Effects" feature adds whiz-bang interface bling that should make Vista and OS X users take notice.

Some Windows power users may prefer the KDE desktop, which more closely resembles Windows. The Kubuntu variant of Feisty Fawn replaces Gnome 2.18 with KDE 3.8.5 as the default interface. (Another variant, Xubuntu, instead provides Xfce 4.4, a lightweight environment that is perfect for an old PC you thought was no longer of any use.)