Tablet PCs are a special kind of notebooks. Usually without keyboard (or equipped with an external and remote keyboard), they feature a touchscreen (therefore they were also named Pen PCs) and access to wireless LAN. In a certain sense they can be compared with PDAs. Microsoft has created a special edition of their operating system for Tablet PCs and published a so-called specification. In 2003 the first Tablet PCs according to this specification entered the market. Though there have been appropriate devices with Linux many years before. See the survey of Linux touch screen laptops and the survey of Linux laptops with detachable displays and finally a survey about Linux on Tablet PCs, WebPads, NotePads and PenPCs. They are used for data acquisition in stores, in the field or in hospitals. Or as a book reader or webbrowser (therefore they are also named WebPads). Their hardware features require some dedicated Linux solutions.