The WKS format is used by Microsoft Works to store spreadsheet information.
Microsoft Works is an office suite available from the Microsoft Corporation. It is considered by most to be a smaller, less expensive version of the Microsoft Office suite; it includes the Microsoft Works word processor, the Works spreadsheet, and the Works database.
Microsoft's Word is able to open (and save as) Works word processor documents, and Microsoft's Excel is able to open (and save as) Works spreadsheets.
