Files with a WKS file extension can only spreadsheet files whether it is associated (more common) with a Microsoft Works Spreadsheet application or IBM’s Lotus 1, 2 and 3. The file extension WKS in both cases stands for “worksheet” and therefore contains data in a spreadsheet.
Spreadsheets are made up of rows and columns of data that are usually used to store and manipulate figures and other numerical information. But of course a WKS file doesn’t only store data in rows and columns, it also stored variable graphs and charts which transforms dynamically depending on the content of the rows and columns in the spreadsheet. WKS also supports formatting to improve data readability and emphasis of information.
Aside from worksheets, files with a WKS file extension may also be linked to an XLISP Workspace document, though this is a less common case. XLISP Workspace is the development environment used for XLISP programming language and it uses the WKS file extension to store important programming environment data that can be accessed every time the environment is used. XLISP is a derivative or higher version of a more popular LISP language and it has more object-oriented features than LISP.
Obviously though, WKS files that are linked with XLISP Workspace can only be opened and modified using the same program. The same goes with WKS files associated with Microsoft Works, though Microsoft Excel can access WKS files made in Microsoft Works too. But of course Microsoft Excel supports and uses its native file extension more (XLS) than WKS. WKS files created in Lotus 1,2 and 3 on the other hand can be opened by the program itself as well as a bunch of other applications such as Microsoft Excel, OpenOffice Calc, Gnumeric, Planamesa Neo Office and Star Office Calc.