Defination of Microsoft Excel and Early history

Microsoft Excel

Microsoft Excel is a spreadsheet application developed by Microsoft for Microsoft Windows, Mac OS X, and iOS. It features calculation, graphing tools, pivot tables, and a macro programming language called Visual Basic for Applications. It has been a very widely applied spreadsheet for these platforms, especially since version 5 in 1993, and it has replaced Lotus 1-2-3 as the industry standard for spreadsheets. Excel forms part of Microsoft Office.

Basic operation

Microsoft Excel has the basic features of all spreadsheets, using a grid of cells arranged in numbered rows and letter-named columns to organize data manipulations like arithmetic operations. It has a battery of supplied functions to answer statistical, engineering and financial needs. In addition, it can display data as line graphs, histograms and charts, and with a very limited three-dimensional graphical display. It allows sectioning of data to view its dependencies on various factors for different perspectives (using pivot tables and the scenario manager). It has a programming aspect, Visual Basic for Applications, allowing the user to employ a wide variety of numerical methods, for example, for solving differential equations of mathematical physics, and then reporting the results back to the spreadsheet. It also has a variety of interactive features allowing user interfaces that can completely hide the spreadsheet from the user, so the spreadsheet presents itself as a so-called application, or decision support system (DSS), via a custom-designed user interface, for example, a stock analyzer, or in general, as a design tool that asks the user questions and provides answers and reports. In a more elaborate realization, an Excel application can automatically poll external databases and measuring instruments using an update schedule, analyze the results, make a Word report or PowerPoint slide show, and e-mail these presentations on a regular basis to a list of participants.

Use of a user-defined function sq(x) in Microsoft Excel. The named variables x & y are identified in theName Manager. The function sq is introduced using the Visual Basic editor supplied with Excel.

Subroutine in Excel calculates the square of named column variable x read from the spreadsheet, and writes it into the named column variable y.

Graph made using Microsoft Excel

Microsoft allows for a number of optional command-line switches to control the manner in which Excel starts.

Macro programming

The Windows version of Excel supports programming through Microsoft's Visual Basic for Applications (VBA), which is a dialect of Visual Basic. Programming with VBA allows spreadsheet manipulation that is awkward or impossible with standard spreadsheet techniques. Programmers may write code directly using the Visual Basic Editor (VBE), which includes a window for writing code, debugging code, and code module organization environment. The user can implement numerical methods as well as automating tasks such as formatting or data organization in VBA and guide the calculation using any desired intermediate results reported back to the spreadsheet.

VBA was removed from Mac Excel 2008, as the developers did not believe that a timely release would allow porting the VBA engine natively to Mac OS X. VBA was restored in the next version, Mac Excel 2011.

A common and easy way to generate VBA code is by using the Macro Recorder. The Macro Recorder records actions of the user and generates VBA code in the form of a macro. These actions can then be repeated automatically by running the macro. The macros can also be linked to different trigger types like keyboard shortcuts, a command button or a graphic. The actions in the macro can be executed from these trigger types or from the generic toolbar options. The VBA code of the macro can also be edited in the VBE. Certain features such as loop functions and screen prompts by their own properties, and some graphical display items, cannot be recorded, but must be entered into the VBA module directly by the programmer. Advanced users can employ user prompts to create an interactive program, or react to events such as sheets being loaded or changed.

Users should be aware that using Macro Recorded code may not be compatible from one version of Excel to another. Some code that is used in Excel 2010 can not be used in Excel 2003. Making a Macro that changes the cell colors and making changes to other aspects of cells may not be backward compatible.

VBA code interacts with the spreadsheet through the Excel Object Model, a vocabulary identifying spreadsheet objects, and a set of supplied functions or methods that enable reading and writing to the spreadsheet and interaction with its users (for example, through custom toolbars or command bars and message boxes). User-created VBA subroutines execute these actions and operate like macros generated using the macro recorder, but are more flexible and efficient.

History

From its first version Excel supported end user programming of macros (automation of repetitive tasks) and user defined functions (extension of Excel's built-in function library). In early versions of Excel these programs were written in a macro language whose statements had formula syntax and resided in the cells of special purpose macro sheets (stored with file extension .XLM in Windows.) XLM was the default macro language for Excel through Excel 4.0. Beginning with version 5.0 Excel recorded macros in VBA by default but with version 5.0 XLM recording was still allowed as an option. After version 5.0 that option was discontinued. All versions of Excel, including Excel 2010 are capable of running an XLM macro, though Microsoft discourages their use.

Charts

Excel supports charts, graphs, or histograms generated from specified groups of cells. The generated graphic component can either be embedded within the current sheet, or added as a separate object.

These displays are dynamically updated if the content of cells change. For example, suppose that the important design requirements are displayed visually; then, in response to a user's change in trial values for parameters, the curves describing the design change shape, and their points of intersection shift, assisting the selection of the best design.

Data storage and communication

Number of rows and columns

Versions of Excel up to 7.0 had a limitation in the size of their data sets of 16K (2¹⁴ = 16384) rows. Versions 8.0 through 11.0 could handle 64K (2¹⁶ = 65536) rows and 256 columns (2⁸ as label 'IV'). Version 12.0 can handle 1M (2²⁰ = 1048576) rows, and 16384 (2¹⁴ as label 'XFD') columns.

File formats

Excel Spreadsheet

Filename extension	.xls, (.xlsx, .xlsm, .xlsb - Excel 2007)
Internet media type	application/vnd.ms-excel
Uniform Type Identifier (UTI)	com.microsoft.excel.xls[19]
Developed by	Microsoft
Type of format	Spreadsheet

Microsoft Excel up until 2007 version used a proprietary binary file format called Excel Binary File Format (.XLS) as its primary format. Excel 2007 uses Office Open XML as its primary file format, an XML-based format that followed after a previous XML-based format called "XML Spreadsheet" ("XMLSS"), first introduced in Excel 2002.

Although supporting and encouraging the use of new XML-based formats as replacements, Excel 2007 remained backwards-compatible with the traditional, binary formats. In addition, most versions of Microsoft Excel can read CSV, DBF, SYLK, DIF, and other legacy formats. Support for some older file formats was removed in Excel 2007. The file formats were mainly from DOS-based programs.

Binary

OpenOffice.org has created documentation of the Excel format. Since then Microsoft made the Excel binary format specification available to freely download.

Using other Windows applications

Windows applications such as Microsoft Access and Microsoft Word, as well as Excel can communicate with each other and use each other's capabilities. The most common are Dynamic Data Exchange: although strongly deprecated by Microsoft, this is a common method to send data between applications running on Windows, with official MS publications referring to it as "the protocol from hell". As the name suggests, it allows applications to supply data to others for calculation and display. It is very common in financial markets, being used to connect to important financial data services such as Bloomberg and Reuters.

OLE Object Linking and Embedding: allows a Windows application to control another to enable it to format or calculate data. This may take on the form of "embedding" where an application uses another to handle a task that it is more suited to, for example a PowerPoint presentation may be embedded in an Excel spreadsheet or vice versa.

Using external data

Excel users can access external data sources via Microsoft Office features such as (for example) .odc connections built with the Office Data Connection file format. Excel files themselves may be updated using a Microsoft supplied ODBC driver.

Excel can accept data in real time through several programming interfaces, which allow it to communicate with many data sources such as Bloomberg and Reuters (through addins such as Power Plus Pro).

• DDE : "Dynamic Data Exchange" uses the message passing mechanism in Windows to allow data to flow between Excel and other applications. Although it is easy for users to create such links, programming such links reliably is so difficult that Microsoft, the creators of the system, officially refer to it as "the protocol from hell". In spite of its many issues DDE remains the most common way for data to reach traders in financial markets.
• Network DDE Extended the protocol to allow spreadsheets on different computers to exchange data. Starting with Windows Vista, Microsoft no longer supports the facility.
• Real Time Data : RTD although in many ways technically superior to DDE, has been slow to gain acceptance, since it requires non-trivial programming skills, and when first released was neither adequately documented nor supported by the major data vendors.

Alternatively, Microsoft Query provides ODBC-based browsing within Microsoft Excel.

Export and migration of spreadsheets

Programmers have produced APIs to open Excel spreadsheets in a variety of applications and environments other than Microsoft Excel. These include opening Excel documents on the web using either ActiveX controls, or plugins like the Adobe Flash Player. The Apache POI opensource project provides Java libraries for reading and writing Excel spreadsheet files. Excel Package is another open-source project that provides server-side generation of Microsoft Excel 2007 spreadsheets. PHPExcel is a PHP library that converts Excel5, Excel 2003, and Excel 2007 formats into objects for reading and writing within a web application. Excel Services is a current .NET developer tool that can enhance Excel's capabilities. Excel spreadsheets can be accessed from Python with xlrd and openpyxl. js-xlsx and js-xls can open Excel spreadsheets from JS.

Versions

Early history

Microsoft originally marketed a spreadsheet program called Multiplan in 1982. Multiplan became very popular on CP/M systems, but on MS-DOS systems it lost popularity toLotus 1-2-3. Microsoft released the first version of Excel for the Macintosh on September 30, 1985, and the first Windows version was 2.05 (to synchronize with the Macintosh version 2.2) in November 1987. Lotus was slow to bring 1-2-3 to Windows and by 1988 Excel had started to outsell 1-2-3 and helped Microsoft achieve the position of leading PC software developer. This accomplishment, dethroning the king of the software world, solidified Microsoft as a valid competitor and showed its future of developing GUIsoftware. Microsoft pushed its advantage with regular new releases, every two years or so.

Microsoft Windows

Excel 2.0 is the first version of Excel for Intel platform. There never was an Excel 1.0 for DOS or Windows.

Excel 2.0 (1987)

The first Windows version was labeled "2" to correspond to the Mac version. This included a run-time version of Windows.

Excel 3.0 (1990)

Included toolbars, drawing capabilities, outlining, add-in support, 3D charts, and many more new features.

Excel 4.0 (1992)

Introduced auto-fill.

Also, an easter egg in Excel 4.0 reveals a hidden animation of a dancing set of numbers 1 through 3, representing Lotus 1-2-3, which was then crushed by an Excel logo.

Excel 5.0 (1993)

With version 5.0, Excel has included Visual Basic for Applications (VBA), a programming language based on Visual Basic which adds the ability to automate tasks in Excel and to provide user-defined functions (UDF) for use in worksheets. VBA is a powerful addition to the application and includes a fully featured integrated development environment (IDE).Macro recording can produce VBA code replicating user actions, thus allowing simple automation of regular tasks. VBA allows the creation of forms and in‑worksheet controls to communicate with the user. The language supports use (but not creation) of ActiveX (COM) DLL's; later versions add support for class modules allowing the use of basic object-oriented programming techniques.

The automation functionality provided by VBA made Excel a target for macro viruses. This caused serious problems until antivirus products began to detect these viruses.Microsoft belatedly took steps to prevent the misuse by adding the ability to disable macros completely, to enable macros when opening a workbook or to trust all macros signed using a trusted certificate.

Versions 5.0 to 9.0 of Excel contain various Easter eggs, including a "Hall of Tortured Souls", although since version 10 Microsoft has taken measures to eliminate such undocumented features from their products.

Excel 95 (v7.0)

Microsoft Excel 95

Released in 1995 with Microsoft Office for Windows 95, this is the first major version after Excel 5.0, as there is no Excel 6.0.

Internal rewrite to 32-bits. Almost no external changes, but faster and more stable.

Excel 97 (v8.0)

Included in Office 97 (for x86 and Alpha). This was a major upgrade that introduced the paper clip office assistant and featured standard VBA used instead of internal Excel Basic. It introduced the now-removed Natural Language labels.

This version of Excel includes a flight simulator as an Easter Egg.

Excel 2000 (v9.0)

Microsoft Excel 2000

Included in Office 2000. This was a minor upgrade, but introduced the upgrade to the clipboard where it can hold multiple objects at once. The Office Assistant, whose frequent unsolicited appearance in Excel 97 had annoyed many users, became less intrusive.

Excel 2002 (v10.0)

Included in Office XP. Very minor enhancements.

Excel 2003 (v11.0)

Included in Office 2003. Minor enhancements, most significant being the new Tables.

Excel 2007 (v12.0)

Microsoft Excel 2007

Included in Office 2007. This release was a major upgrade from the previous version. Similar to other updated Office products, Excel in 2007 used the new Ribbon menu system. This was different from what users were used to, and was met with mixed reactions. One study reported fairly good acceptance by users except highly experienced users and users of word processing applications with a classical WIMP interface, but was less convinced in terms of efficiency and organisation. However, an online survey reported that a majority of respondents had a negative opinion of the change, with advanced users being "somewhat more negative" than intermediate users, and users reporting a self-estimated reduction in productivity.

Added functionality included the SmartArt set of editable business diagrams. Also added was an improved management of named variables through the Name Manager, and much improved flexibility in formatting graphs, which allow (x, y) coordinate labeling and lines of arbitrary weight. Several improvements to pivot tables were introduced.

Also like other office products, the Office Open XML file formats were introduced, including .xlsm for a workbook with macros and.xlsx for a workbook without macros.

Specifically, many of the size limitations of previous versions were greatly increased. To illustrate, the number of rows was now 1,048,576 (2²⁰) and columns was 16,384 (2¹⁴; the far-right column is XFD). This changes what is a valid A1 reference versus a named range. This version made more extensive use of multiple cores for the calculation of spreadsheets; however, VBA macros are not handled in parallel and XLL add‑ins were only executed in parallel if they were thread-safe and this was indicated at registration.

Excel 2010 (v14.0)

Microsoft Excel 2010 running on Windows 7

Included in Office 2010, this is the next major version after v12.0, as version number 13 was skipped.

Minor enhancements and 64-bit support, including the following:

• Multi-threading recalculation (MTR) for commonly used functions
• Improved pivot tables
• More conditional formatting options
• Additional image editing capabilities
• In-cell charts called sparklines
• Ability to preview before pasting
• Office 2010 backstage feature for document-related tasks
• Ability to customize the Ribbon
• Many new formulas, most highly specialized to improve accuracy

Excel 2013 (v15.0)

Included in Office 2013, along with a lot of new tools included in this release:

• Improved Multi-threading and Memory Contention
• FlashFill
• Power View
• PowerPivot
• Timeline Slicer
• Windows App
• Inquire
• 50 new functions

Apple Macintosh

• 1985 Excel 1.0
• 1988 Excel 1.5
• 1989 Excel 2.2
• 1990 Excel 3.0
• 1992 Excel 4.0
• 1993 Excel 5.0 (part of Office 4.X—Motorola 68000 version and first PowerPC version)
• 1998 Excel 8.0 (part of Office 98)
• 2000 Excel 9.0 (part of Office 2001)
• 2001 Excel 10.0 (part of Office v. X)
• 2004 Excel 11.0 (part of Office 2004)
• 2008 Excel 12.0 (part of Office 2008)
• 2011 Excel 14.0 (part of Office 2011)

OS/2

• 1989 Excel 2.2
• 1990 Excel 2.3
• 1991 Excel 3.0