The MW extension is given to files that are associated with a technical calculation application called Maple. MW files are used to store the worksheet created in the program. It may contain mathematical formulas, graphs, equations. Such files may also store other data, e.g. comments. MW is a text file written in the XML markup language. It is a tool used in engineering and by mathematicians.

MW is an extension used in Maple 9 and following. Older versions of the program used the MWS extension when saving sheets.