The term "whiteboard" is also used to refer to interactive whiteboards. All classrooms include Promethean World interactive whiteboards. The initial whiteboards, analogous to blackboards, date from the late 1950s. Interactive whiteboards are present in all classrooms. The term is also used for things that remove marks from chalkboards and whiteboards. All classrooms are equipped with interactive whiteboards, which are linked with the given classroom's computer. It features over 70 classrooms, each fitted with interactive whiteboards. Every school is equipped with labs featuring Macintosh computers, plasma displays, and interactive whiteboards. Interactive whiteboards allow learners and instructors to write on the touch screen. Interactive products such as smartphones, iPad's/iPod's, interactive whiteboards and websites are all easy to use. A few interactive whiteboards can automatically detect projected images during a different type of calibration. Some rastra hold markers for use on whiteboards. The first interactive whiteboards were designed and manufactured for use in the office. Dry-erase markers for whiteboards were invented in 1975. In 2019, ViewSonic announced myViewBoard, a proprietary software solution for digital whiteboards.