.ET File Extension

Spreadsheet created by Kingsoft Spreadsheets, a free application similar to Microsoft Excel; saves a spreadsheet in the form of rows and columns; also supports formulas and charts; used as the native spreadsheet format for the software, but can be converted to an .XLS or .XLSX file usable by Microsoft Excel.

Teaching lesson created by Easiteach, a program that allows teachers to develop classroom lessons and deliver them through an interactive interface; contains lesson data such as layouts, navigation, images, text, themes, and animations.