XLS file

File extension	.xls
Category	Document File
Description	Microsoft Excel is a commercial spreadsheet application written and distributed by Microsoft for Microsoft Windows and Mac OS X. Pre-2007 versions of Excel use XLS as the primary format for saving files. It features calculation, graphing tools, pivot tables, and a macro programming language called Visual Basic for Applications. It has been a very widely applied spreadsheet for these platforms, especially since version 5 in 1993, and it has almost completely replaced Lotus 1-2-3 as the industry standard for spreadsheets. Excel forms part of Microsoft Office. The current versions are 2010 for Microsoft Windows and 2011 for Mac OS X.
Actions	XLS Converter View other document file formats
Technical Details	Microsoft Excel up until 2007 version used a proprietary binary file format called Binary Interchange File Format (BIFF) as its primary format. Used as the basis for XLS files it is a persistence format that supports authoring and manipulating content in workbooks and workbook templates. Most versions of Microsoft Excel can read CSV, DBF, SYLK, DIF, and other legacy formats.
Associated programs	Microsoft Excel Microsoft Excel Viewer OpenOffice
Developed by	Microsoft
MIME type	application/vnd.ms-excel
Useful links	More detail about the XLS format How to open an XLS file without Microsoft Excel Microsoft Office binary file format specifications XLS Converter

Using Zamzar it is possible to convert XLS files to a variety of other formats

This page contains information on the XLS file extension (Microsoft Excel Spreadsheet), a popular document file format