As computers shrink in size, the line between mini-PCs and small desktop PCs is getting blurrier every year. As the name suggests, however, mini-PCs, are smaller than usual, usually less than five inches square and a few inches tall, making them easier to carry and hide away on a crowded desktop or behind a signage or kiosk display. They're also usually fanless, which means they're quiet and have one less moving part to break, and they tend to be cheaper, with more limited I/O. That usually translates into lower prices.Here we take a look at 10 capable mini-PCs that can be purchased pre-installed with a Linux operating system. (Click on the Gallery link below for a slide show of photos and descriptions.) To keep the selection manageable, we are skipping the many, mostly media player oriented devices that ship with Android only, such as the Tronsmart Orion R28. Most of these devices can be used as media players, although most are more generic systems that can be used as desktop replacements or for signage and/or other embedded applications.