By 1982, VisiCalc's price had risen from $100 to $250. Several competitors appeared in the market, notably SuperCalc and Multiplan, each of which added more features and corrected deficiencies in VisiCalc, but could not overcome its market dominance. A more dramatic change occurred with the 1983 launch of Lotus Development Corporation's Lotus 1-2-3, written by former Personal Software/VisiCorp employee Mitch Kapor, who had written VisiTrend and VisiPlot. Unlike the PC version of VisiCalc, 1-2-3 was written to take full advantage of the PC's increased memory, screen and performance. Yet it was designed to be as compatible as possible with VisiCalc, including the menu structure, to allow VisiCalc users to easily migrate to 1-2-3.