.12M File Extension
File TypeLotus 1-2-3 SmartMaster File
File format categories include Binary, Text, XML, and Zip. The format of this file type has not been determined.
What is a 12M file?
A 12M file is a spreadsheet created by Lotus 1-2-3, which is part of IBM Lotus SmartSuite. It contains a pre-designed spreadsheet that allows a user to enter information to create forecasts, financial statements, and budgets. 12M files also include formulas, formatting, and print ranges.
Lotus 1-2-3 was first developed by Lotus Development Corporation, which was bought by IBM in 1995. The "1-2-3" refers to the program's three main capabilities: 1) spreadsheet functions, 2) creating charts and graphs, and 3) basic database operations.
NOTE: Lotus 1-2-3 was popular in the 1980s and early-90s. However, it was overtaken by Microsoft Excel in the 90s and was officially discontinued in 2013.