Microsoft Excel is a spreadsheet program written and distributed by Microsoft for computers using the Microsoft Windows operating system and Apple Macintosh computers. It is overwhelmingly the dominant spreadsheet application available for these platforms and has been so since version 5 (1993) and its bundling as part of Microsoft Office. It was originally developed for the Mac in 1985 and the first Windows version (1987) was therefore version 2.0. The current version is 11, also called Microsoft Office Excel 2003.
Spreadsheets were the original "killer application" for personal computers, and as such, when Excel was bundled with Microsoft Word and Microsoft PowerPoint in the Microsoft Office package, the interfaces for those two programs were redesign to be consistent with that of Excel.
Early in its life Excel became the target of a copyright lawsuit by another company already selling a software package named "Excel." As the result of the dispute Microsoft was required to refer to the program as "Microsoft Excel" in all of its formal press releases and legal documents. However, over time this practice has slipped.
Excel has extensive graphing capabilities, added support for Visual Basic for Applications as a scripting language in 1993 (which makes it a prime target for macro viruses), and offers a large number of user interface tweaks, but its essence is little different from the original spreadsheet, VisiCalc.
Most versions often have a easter egg.