Definition

The current widely-used definition for UMPC is: A mobile device with diagonal screen size from 4"-10" running any OS and supporting more than one computing/communication function.

Further Details:
Power - A mobile device has a battery by definition (at least for now)
Hardware Platform - No restriction
Touch screen - Common but not required

Historical context

The term UMPC was first used for mobile devices with 7" diagonal screen marketed in 2006 by Samsung, ASUS, Founder (Intel based) and TabletKiosk (VIA based). These devices were tablets with touch capability running Windows tablet edition or Windows XP with touch pack from Microsoft. Origami was the touch pack and basic touch interface skin from Microsoft on these devices.

Intel's first introduction of the UMPC concept was referred to as "handtop" by Intel CEO Paul Otellini, but was later dropped in favor of UMPC.

Intel began to deemphasize the term UMPC in the Spring of 2008 and now prefers talking about "MID," the Mobile Internet Device. Most of Intel-based MIDs currently under development are merely a better realization of the original UMPC concept. In fact, now VIA refers to their devices as MID as well. Meanwhile the ARM camp has increased performance and still keeping power low thus enabling some very interesting portable devices.

Even while Intel was deemphasizing UMPC, it was quietly taking off in the form of clamshell (or "netbook") device. Both Asus and Inventec, who worked on early UMPC were first quietly, and then openly, using "Intel UMPC hardware" in 7" clamshells. ASUS EEMPC and Inventec S37 (sold as VYE and Kohjinsha) was the result. This started a race among all laptop vendors to jump into UMPC space. Now Aspire is Acer's entry in this field, HP has 2133 and Dell is rumored to be coming out with there own UMPC.

Latest announcements from Qualcomm about their platform Snapdragon, indicate it is based on ARM core, with integrated WLAN and GPS, and will enable some amazing MID/UMPCs. Intel and VIA (already encumbered by Intel technology licensing issues) have there work cut out to produce competing products. The Genie is out of the bottle and it is great time for designers and consumers. Thank you Intel/VIA and Microsoft for starting this product trend.

Here are pictures of some pre-"UMPC" UMPCs:

First, the Sony U50 And the OQO

And now, the first official UMPCs:

Samsung Q1 - designed and implemented by Samsung with collaboration with Intel/Microsoft

Founder H70 - Designed by Intel, implemented by ECS

ASUS R2H - designed and implemented by Asus with collaboration with Intel/Microsoft

And, TabletKiosk EO - designed and implemented by Amtek, with collaboration with MICROSOFT and VIA