.ETX File Extension
File Type 1TeX Font Encoding File
What is an ETX file?
Font file used by TeX and LaTeX typesetting systems; saved in a plain text format and contains markup that describes how a font is encoded for its appearance; allows font customization for TeX documents.
File Type 2Structure Enhanced Text (Setext) File
.ETX File Association 2
ASCII text file format known as "Setext" that is used to distribute information over the Internet; can be opened with EasyView or another Setext viewer; may also be readable with a basic text editor, though the text formatting will be lost.