Linux

Introduced in 1991, Linux boasts an estimated 67 million users worldwide according to linuxcounter.net. Free versions abound, but companies adopting Linux as part of critical infrastructure typically require more support than a community of unpaid, albeit enthusiastic, volunteers can provide.

A programmer looks at the current versions of five well-known text editors and offers his take on how well they perform.

Our Linux pros check out the decked-out XPS 13 'Developer Edition' laptop, preloaded with Ubuntu and other tools.

There used to be a time when Microsoft Windows ruled the operating system world. But in recent years, the free and open source Linux operating system has taken a big bite out of Windows' dominance. But Linux has always had an image problem of seeming too difficult and unwieldy to install and learn, with a steep learning curve attached.

They're incredibly small and surprisingly powerful: We tell you what these devices are capable of, and how well they perform.

Running games during the DOS era was trouble enough, and today exploring those old games can be a nightmare. Sound card issues, memory management and other peculiarities of early PC gaming amplified as OS technology progressed and passed these titles by, leaving many of them orphaned and unable to run on modern systems. Today's answer to this problem isn't digging up an old system or rooting around for special drivers, it's emulation: free and open-source DOSBox.

Claws Mail is a great basic email client on its native Linux platform, and the Windows port I looked at is done very nicely. It lacks automatic account configuration à la Outlook, but it supports multiple accounts, filters, and has a threaded view of messages. It's attractively simple, but could use a better way to import existing email and addresses.

When Ubuntu decided last year to abruptly replace the familiar Gnome UI with its own Unity interface, many users were upset. And according to the latest numbers from DistroWatch, Linux Mint has been the major beneficiary, so we decided to test Linux Mint 12.

"Live" distributions of Linux offer a wonderful convenience for those not quite ready to commit to the open-source operating system. By booting Linux directly from a CD (which you burn from a downloaded .iso file), you can try it out without first installing it onto your hard drive. But live Linux CDs have their problems. Optical media is slow. It's also read-only, limiting your ability to configure the operating system. Finally, many of today's netbooks and ultraportable laptops don't have an optical drive. The Universal USB Installer (free) offers a simple and elegant solution to those problems.

This image gallery accompanies the ITworld review of OpenSUSE 11.4.

Three years in the making, Red Hat Enterprise Linux ( RHEL) 6 is a gutsy, green upgrade that features native support for KVM, the Linux kernel-based virtual machine.