One of the early (if not the earliest) uses of a throbber occurred in the NCSA Mosaic web browser of the early 1990s, which featured an NCSA logo that animated while Mosaic downloaded a web page. As the user could still interact with the program, the pointer remained normal (and not a busy symbol, such as an hourglass); therefore, the throbber provided a visual indication that the program was performing an action. Clicking on the throbber would stop the page loading; later web browsers added a separate Stop button for this purpose.