EtherCalc - EtherCalc is a web spreadsheet.
RoxyApps Spreadsheet Conversion Tool - Converts csv, et, numbers, xls, xlsx, ods and other spreadsheet files to png, pdf, html, jpg, and other formats
Keikai - Effortlessly Build Spreadsheet-driven Web Apps
XLS to XML - XLS to XML is the name of a portable and cross-platform application for converting the XML file to the XLS and vice versa.
SSuite Axcel Professional Spreadsheet - This powerful and professional spreadsheet has all the tools you need to calculate, analyse, summarize, and present your data in numerical reports or colourful graphics.
XML Converter Standard Edition - XML Converter Standard Edition is a way to transform the data stored in the XML format to XLS format within few minutes.