.WK4 File Extension

Spreadsheet created by IBM Lotus 1-2-3 (v.4), a spreadsheet program included with Lotus SmartSuite; stores data in cells that are organized into rows and columns; each cell can store static data or a formula, which automatically updates the value displayed in the cell.

NOTE: Previous versions of Microsoft Excel could import WK4 files, but Excel 2007 and later does not support the WK4 format.