Subnotebook

A subnotebook (or ultraportable computer) is a small and lightweight portable computer, with most of the features of a standard laptop computer but smaller. The term is often applied to systems that run full versions of desktop operating systems such as Windows or Linux, rather than specialized software such as Windows CE, Palm OS or Internet Tablet OS. The term "ultra-mobile PC" (UMPC) is also frequently used to refer to such machines, although this also refers to a small form-factor tablet PC platform.

Subnotebooks are smaller than laptops but larger than handheld computers and UMPCs. They often have screens, usually measuring 10.6 inches (26.92cm) to 13.3 inches (33.78cm), and a weight less than 1 kg up to about 2 kg; as opposed to full-size laptops with 14.1 (35.81cm) to 15.4 inches (39.12cm) screens and a weight of 2 kg or more. The savings in size and weight are usually achieved partly by omitting ports or having removable media/optical drives; subnotebooks are often paired with docking stations to compensate.

Subnotebooks have been something of a niche computing product and have rarely sold in large numbers until the 2007 introduction of the Asus Eee PC and the OLPC XO-1^[1], known as ultra low-cost PC (ULPC or ULCPC), which are inexpensive in comparison to both existing machines in that form factor, and computers in general.