Dr. Weiser began research in 1988. He realized that the current technology wasn't sufficient to create the vision. He focused first on different features of ubiqutious computing, like devices that were portable and whose location was always known or devices that would make it easier for people to work together. Tabs are similar to little electronic Post-it notes, and there could be hundreds in an office, each corresponding to some small surface with information. Pads were like yellow pads, or scrap computers, meant to be used temporarily and then left for someone else.
Boards are electronic white-boards, to allow group collaboration, and are in use today.
Tabs are discussed in more detail in section 6 .