OQO was a U.S. computer hardware company that was notable for manufacture of handheld computers. Its systems possessed the functionality of a tablet PC in a size slightly larger than a personal digital assistant (PDA). According to Guinness World Records, the "OQO" was the smallest full-powered, full-featured personal computer in 2005. The company's first version of subnotebook computer was the OQO model 01. It had been compared with the Ultra Mobile PC platform, although it was introduced before the UMPC took flight. The company was founded in 2000. OQO was reported to have stopped production in April 2009. The company confirmed that it had ceased operations in May 2009 because of financial difficulties. OQO Model 01 The original OQO model 01 was announced several years before prototypes were even seen, leading many people to call it vaporware until it was finally released in Q3 of 2004. The computer shipped with Windows XP installed (Home Edition or Professional, but the Tablet PC Edition was not available until the model 01+ was released) and featured a 1 GHz Transmeta Crusoe processor, 20 GB hard drive, and 256 MB of RAM. It included USB 1.1, FireWire 400, a headphone port, and a built-in microphone, integrated 802.11b wireless radio, as well as Bluetooth. The OQO used a Wacom electromagnetic induction-type pen stylus with a magnetic field sensitive 800x480 resolution transflective screen. Retail shipments began on October 14, 2004. Its size was and it weighed . OQO Model 01+ The OQO model 01+ was announced and released on September 27, 2005. Representing an incremental update to the model 01, the model 01+ featured a larger 30 GB hard drive, 512 MB of RAM, USB 2.0, and an internal speaker. It also added support for portrait display mode. It also had a redesigned screen bezel intended to improve the accuracy of its Wacom-enabled display by increasing the space between the bezel and edge of the display. Originally it was only available running Windows XP Home or Pro editions. A version with Microsoft Windows XP Tablet PC Edition 2005 was introduced on January 4, 2006, taking advantage of handwriting recognition and improved navigation. OQO Model 02 The OQO model 02 was introduced by Bill Gates in January 2007 at the Consumer Electronics Show in Las Vegas. It weighed and was small enough to fit in a pocket; at the time it was the world's smallest fully-functional Windows