A TM file is a text document created with TeXmacs. It may contain text, graphics, math formulas, and other content in a structured format.

TeXmacs is a free WYSIWYG LaTex editor for Unix. It is used primarily by scientists for creating and editing structured documents. TeXmacs runs natively on Unix systems and can be run on Mac OS X using Fink. WinTeXmacs is a beta version of TeXmacs that can be run on Windows.