The iPAQ is a Pocket PC and personal digital assistant, first unveiled by Compaq in April 2000. The devices use a Windows Mobile interface. In addition to this, there are several Linux distributions that will also operate on some of these devices.
The Pocket PC Devices such as the iPAQ helped me in my early career development during the early 2000s. I designed the interfaces and wrote many programs used in these devices, mostly for physicians and clinics in the USA.