Microsoft Excel is a proprietary spreadsheet-application written for Microsoft Windows and Mac OS X.
It features calculation, graphing tools, pivot tables and, with the exception of Excel 2008 for Mac OS X, a macro programming language called VBA (Visual Basic for Applications).
Since the 1993 release of Microsoft Office, Excel has been the dominant spreadsheet application for these two platforms.
Microsoft originally marketed a spreadsheet program called Multiplan in 1982, which lagged sorely behind Lotus 1-2-3 on MS-DOS systems.
However, Lotus was slow moving to Windows and once Excel overtook Lotus, Microsoft became the number one software development company.
Excel frequently provides new releases.
The latest Windows version is known as Microsoft Office Excel 2007; the latest Mac OS X version is Microsoft Excel 2008.
While Excel has undergone constant upgrades over the years it still resembles VisiCalc, the original spreadsheet that first convinced business people they needed these personal computers over thirty years ago.
VisiCalc presented alphabetic and numeric data in cells, intersections of rows and columns.
Cells also contained formulas referring to other cells.
Lots of things about spreadsheets have changed in the last three decades but the two-dimensional grid remains essentially the same.
Visual Basic for Applications (VBA) programming language is an important part of Excel enabling sophisticated users to define their own functions and automates tasks.
A friend of mine has developed a custom accounting system for a tutoring business using Excel and VBA programs.
This system dramatically reduces the business record-keeping effort and substantially increases data reliability.
However, VBA has been a port of entry for computer viruses.
Excel provides well over a dozen standard types of charts without counting the subcharts.
For example, Pie charts may be broken down into Pie of Pie, Pie with a 3-D visual effect, Bar of Pie, exploded Pie charts and others.
Excel also provides about twenty custom graph types ranging from Area Blocks to Tubes.
A Wizard makes it easy as pie to chart your data, but you may come up with nonsense if you don't know what you're doing.
Excel offers extensive statistical analysis tools.
Help on using these tools is a few clicks away.
But no software will transform a non-statistician into a statistician.
The way I see it for the interesting, complicated cases Excel presents a real danger of generating erroneous, even if good-looking, results.
By the way, it's not a question of professional jealousy; I am not a statistician.
Other criticisms of Excel include its lack of accuracy under certain conditions and its treatment of the year 1900 as a leap year.
(Excel kept Lotus 1-2-3's error so as not to break compatibility.
) Such errors often apply to spreadsheets in general.
But as was the case for VisiCalc way back when, spreadsheet programs are a tremendous help in removing the drudgery from calculations.
They enable business people and others to explore scenarios that formerly required too many tedious calculations.