Microsoft Office Excel is a spreadsheet application written and distributed by Microsoft for Microsoft Windows and Mac OS X as part of the Microsoft Office suite.
A new user-interface design, dubbed the "ribbon", was introduced with Excel 2007 for Windows. A similar UI was introduced to Excel 2011 for OS X.
Excel is the among most widely used spreadsheet programs, especially in business environments. The first version was introduced in 1993, and new versions have been released every 2-3 years since then.