The HP tablet runs Windows 7, and was first previewed by Microsoft at the Consumer Electronics Show in January. HP published some details on its company blog last month and updated the information with a posting Monday that includes two promotional videos. The videos show a tablet device running Flash and responding to hand gestures.

'Not a Watered-Down Internet'

The positioning by tablet makers comes a few weeks before the iPad goes on sale in early April. On Sunday night, Apple showed its first iPad TV ad during the Academy Awards. It showcased the device's ease of use for e-mails, movies, music, photos, news reading, and web searching.

But the iPad is being criticized for several shortcomings, and the posting on the HP blog by Personal Systems Group Chief Technology Officer Phil McKinney emphasized some of those differences.

The HP slate product, McKinney wrote, gives "a full web browsing experience in the palm of your hand," not a "watered-down Internet." In particular, he noted, it has full support for Adobe's ubiquitous Flash technology.

Not coincidentally, Apple's mobile devices do not support Flash, which is used for most of the animation and much of the video shown on the web. In addition to being Flash-less, the iPad also doesn't have a webcam, HDMI high-definition output, GPS or multitasking.

Tablets from Smartphone Makers?

Ross Rubin, director of industry analysis for consumer technology at the NPD Group, noted that the apparent rush of competition following the iPad announcement in January is really the latest in a "long history of tablet-based computing devices." To date, no tablet product has been particularly successful, so the buildup to Apple's announcement was, in part, driven by a curiosity to find out if Apple had figured out a winning formula.

Rubin said that, without Flash support, it's difficult to see how Apple can overcome the "watered-down Internet" criticism, since so many sites use Flash. Apple appears to be "betting that a lot of sites will move to HTML5," he said, which could provide some of Flash's capabilities.

A key move on Apple's part was to build up, by essentially creating a large iPod touch. This meant the iPad can immediately run tens of thousands of applications for the touch, even if the interaction and display specifications for those apps are for a device with a smaller screen.

Microsoft, HP and others are taking the other direction, using Windows 7 on their tablet computers and promoting their devices as full-blown computers.

Rubin pointed out that tablets are also being built around Google's open-source Android operating system, as well as several Linux variations. He predicted that, since the iPad is a "cross between a notebook and a smartphone," we'll see competitive tablet products being released by smartphone makers, like Nokia and Samsung.