Lotus 1-2-3 is a discontinued spreadsheet program from Lotus Software. It was the first killer application of the IBM PC, was hugely popular in the 1980s, and significantly contributed to the success of IBM PC-compatibles in the business market.
Lotus 1-2-3 Release 2.3 for DOS User's Guide; the Functions and Macros Guide is next to it.
A Lotus 1-2-3 box, as seen in an exhibit at the Computer History Museum in 2008
Charting on Lotus 1-2-3 Release 2.2 for DOS
Examples of Lotus 1-2-3 macros
Lotus Software was an American software company based in Massachusetts; it was sold to India's HCL Technologies in 2018.
A book of Lotus Symphony (DOS) Reference Manual, published in 1984
Mitch Kapor