Why would people continue using a twelve-year-old operating system that would put them at risk?

No doubt, many are home users who simply aren't very technology savvy and/or may not have the desire or the money to upgrade to a newer version of Windows. Some probably have older, underpowered PCs that can't run Windows 7 or 8. And others have specific software?often custom business applications?that only runs on Windows XP.

Fortunately, the open source community has free operating systems that meet the needs of users in all of these situations. This month we've put together a list of 50 different applications that can replace Windows XP. It's organized into several different categories. Those that are easiest for beginners to use come first, followed by lightweight operating systems that can run on old hardware, then operating systems that are particularly tailored for business users and open source operating systems that aren't based on Linux. The list ends with a few applications that aren't complete operating systems but do allow users to run their existing XP software from Linux.