Perhaps the first "Killer App" for PC's, Lotus' 1-2-3 character mode DOS spreadsheet was still king in 1991, even though Microsoft's Excel had already been out for several years on Windows, Mac and OS/2. In 1989, Lotus released 1-2-3 version 2.2, which used "Expanded Memory" in order for users to take advantage of the larger memory capabilities of the Intel 286 and 386 chips.
In 1990, Lotus 1-2-3 had a 54 percent share of the market, with Microsoft way in behind at 12 percent. Lotus 1-2-3 had numerous competitors in the space, including Borland's Quattro Pro. While 1-2-3 continued to be popular for many years, eventually, its dominance came to an end with the rise of Windows 3.1 and Excel.
Lotus eventually produced a graphical version for Windows as part of its SmartSuite series of office suites (which included the Ami Pro word processor and the Freelance Graphics presentation application) but it never was able to to return to its glory days and its market share waned.
Today, Lotus 1-2-3's spirit lives on as the Spreadsheet app IBM's Symphony 3 office suite, which is a cross-platform free product that runs on Windows, Linux and Mac.