January 26: Lotus 1-2-3 was released (1983)

Lotus 1-2-3 for DOS

The Lotus Development Corporation released its first spreadsheet program 1-2-3. It outsold then-most-popular spreadsheet program VisiCalc in the same year and had been the market leading spreadsheet for DOS for years until Microsoft released it spreadsheet Excel. 1-2-3 became a killer application for DOS and had been a test application to evaluate the compatibility of clone PCs along with Microsoft Flight Simulator. The company later developed a groupware and email system Lotus Notes in collaboration with Ray Ozzie's Iris Associates and Lotus Notes became a big success. IBM purchased the company in 1995 for $3.5 billion, primarily to acquire Lotus Notes, and change the company name to Lotus Software.