.123 File Extension

Lotus 1-2-3 Spreadsheet

Developer IBM
3.8  |  70 Votes

What is a 123 file?

A 123 file is a spreadsheet created by Lotus 1-2-3, or exported by another spreadsheet program, such as Corel Quattro Pro. It stores data in rows and columns and supports functions that can be applied to the data in various cells, which can automatically populate the data in other cells. 123 files may contain various spreadsheets, such as financial budgets and quarterly earnings.

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Screenshot of a .123 file in Corel Quattro Pro 2021
123 file open in Corel Quattro Pro 2021

Lotus 1-2-3 was first developed by Lotus Development Corporation, which was bought by IBM in 1995 and integrated into part of IBM Lotus SmartSuite. 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.

The 123 file format is a proprietary format introduced with the release of the 97 Edition of Lotus 1-2-3 in 1997. The format replaced the .WK4 format introduced with version 4 of Lotus 1-2-3.

How to open a 123 file

You can open 123 files with Lotus 1-2-3, but IBM no longer develops the software. Other third-party applications that support 123 files include Corel Quattro Pro (Windows), OpenOffice Calc (multiplatform), Planamesa NeoOffice (macOS), and Gnumeric (Linux).

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Programs that open 123 files

IBM Lotus 1-2-3  —  Discontinued

PCB123 Circuit Board Design

Developer Sunstone Circuits
3.5  |  18 Votes

Printed circuit board (PCB) layout created with PCB123, a PCB design program; contains a circuit board design, which can include multiple components; supports 2, 4, and 6-layer circuit boards with soldermask and silkscreen options.

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Completed PCB123 designs can be sent to Sunstone Circuits for manufacturing. Assembly quotes are provided within the program.

Programs that open 123 files

Category: CAD Files
Updated: November 12, 2009

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