VisiCalc was the "killer app" that launched Apple. It was strategically huge for IBM to get it converted to the original IBM PC. Long ago on a Saturday I am working in our store and a guy walks in and tells me that he is visiting the area and wanted to use an IBM PC XT on display to show his Aunt some software he wrote.
That guy - Mitch Kapor founder of Lotus.
The software - Lotus 1-2-3.
I said yes. He loaded his pre-release version of Lotus 1-2-3 and gave his Aunt a demo while I watched. Wow! It blew VisiCalc away and quickly became the application that every business professional had to have. It is sad to see IBM kill the Lotus brand. Much like Novell and WordPerfect it was an example of a big company buying and then breaking the number one product in its category. Here's the story of its demise and what IBM is doing next: https://bit.ly/QC6XWP