Worksheet file (Microsoft Excel)
XLS is a file extension for a spreadsheet file format created by Microsoft for use with Microsoft Excel. XLS stands for eXceL Spreadsheet.
Microsoft Excel files use a proprietary format for storing Microsoft Excel documents. This file format is known as the Binary Interchange File Format (BIFF). Data inside all Office Document files are stored in series of fixed-size streams. The location of each fixed-size stream is described by several sector allocation tables. These streams contain meta-data information about the document, such as the author name, subject, and individual sheet names. XLS files can also be opened by the Microsoft Excel Viewer, and OpenOffice.
MIME type: application/vnd.ms-excel, application/msexcel, application/x-msexcel, application/x-ms-excel, application/vnd.ms-excel, application/x-excel, application/x-dos_ms_excel, application/xls
Learn more about .XLS files:
Visit the Microsoft Excel web page
See answers to Excel file-related questions at ITKnowledgeExchange.com.