Definition - What does Lotus 1-2-3 mean?
Lotus 1-2-3 was a spreadsheet program developed by Lotus Software, which is now part of IBM, and was first released on January 26, 1983. Lotus 1-2-3 was not the first spreadsheet application, but because of its capabilities it became the industry standard throughout the 1980s and '90s.
Techopedia explains Lotus 1-2-3
Lotus 1-2-3 was originally developed by Jonathan Sachs, who had already developed two spreadsheet applications while employed at Concentric Data Systems. Lotus itself was founded by Mitchell Kapor, who was a friend of the developers of VisiCalc, the number-one spreadsheet program at the time.
Its design was very similar to that of VisiCalc, including the A1 notation for cells and the slash-menu structure, but made some improvements, particularly in performance since it was cleanly programmed in x86 assembly language and mostly bug-free. It wrote directly to the video memory rather than resorting to using slow DOS and BIOS output functions like other spreadsheets at the time. This remained true until version 3.0 where Lotus switched to using C, which caused delays because it had to be made portable across different platforms and be made compatible with newer and existing macro sets and formats.
This spreadsheet software was the most popular one until Windows became popular in the early '90s, when many of Lotus' customers started switching to MS Excel, which was released in 1985 for the Macintosh and later in 1987 with the release of Windows 2.2. After more than three decades in service and countless versions later, it was discontinued in 2013, being pulled from the market on June 11, 2013, and support officially ending on September 30, 2014.