Wal-Mart, the most mass-market retailer imaginable, is committing an outrageous form of computing heresy: On its Web site, it's selling Windows-compatible personal computers without Windows

Stranger yet, the PCs (built by Microtel Computer Systems, a Los Angeles area manufacturer) come installed with a version of Linux, the open-source operating system that has been giving Microsoft fits lately. The computers sell for less than many comparable Windows systems -- $299 for a basic machine, sans monitor, with a roughly 10-gigabyte hard drive, 128 megabytes of memory, a CD-ROM drive, Ethernet, a modem and an 850MHz AMD Duron processor ($599 doubles the memory, quadruples the hard drive, and upgrades you to a CD-RW drive and a 1.8GHz Pentium 4 processor). To make this break with industry tradition, Wal-Mart didn't work with experienced Linux distributors such as Red Hat. It went with Lindows.com, a San Diego start-up headed by MP3.com founder Michael Robertson. Lindows says it wants to sell to home and small-business users, not computing veterans. A lot of Linux developers say such things, but Lindows bundles two nifty features to support that goal. One is single-click installation of software from a Web archive. Another is a program that lets you run regular Windows applications in Linux.