What is lotus 1-2-3?
Lotus 1-2-3 was a spreadsheet program developed by Lotus Software that is now part of IBM and was first released on January 26, 1983. Lotus 1-2-3 wasn't the first spreadsheet application, but rather because of its capabilities it became the industry standard in the 80s and 90s.
Lotus 1-2-3 was originally developed by Jonathan Sachs, who had already developed two spreadsheet applications at Concentric Data Systems. Lotus itself was founded by Mitchell Kapor, a friend of the developers of VisiCalc, the leading spreadsheet program at the time.
Its design was very similar to VisiCalc's, including the A1 notation for cells and the slash menu structure, but made some improvements, particularly in performance, as it was neatly programmed in the x86 assembly language and was mostly bug free. It wrote directly to video memory instead of resorting to slow DOS and BIOS output functions like other tables at the time. This was true up to version 3.0, when Lotus switched to using C, which led to delays as it had to be made portable to different platforms and made compatible with newer and existing macro sets and formats.
This spreadsheet software was the most popular until Windows became popular in the early 1990s when many customers switched from Lotus to MS Excel, which was released for the Macintosh in 1985 and later with the release of Windows 2.2 in 1987. After more than three decades in service and countless later versions, it was discontinued in 2013 and taken off the market on June 11, 2013. Support officially ends on September 30, 2014.