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Microsoft Excel is a spreadsheet application developed by Microsoft for Microsoft Windows and Mac OS X. 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.
 Excellent examples are developed that show just how applications can be designed.
 In a more elaborate realization, an Excel application can automatically poll external databases and measuring instruments using an update schedule,
Some form of data acquisition hardware is required. See, for example, 
 analyze the results, make a Word report or Power Point slide show, and e-mail these presentations on a regular basis to a list of participants.
thumb|300px|Use of a user-defined function sq(x) in Microsoft Excel. The named variables x & y are identified in the Name Manager. The function sq is introduced using the Visual Basic editor supplied with Excel.
thumb|300px|Subroutine in Excel calculates the square of named column variable x read from the spreadsheet, and writes it into the named column variable y.
thumb|right|300px|Graph made using Microsoft Excel
Microsoft allows for a number of optional command-line switches to control the manner in which Excel starts.
==VBA 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
For example, by converting to Visual Basic the recipes in Code conversion to Basic from Fortran probably is easier than from C++, so the 2nd edition (isbn=0521437210) may be easier to use, or the Basic code implementation of the first edition: 
 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.However an increasing proportion of Excel functionality is not captured by the Macro Recorder leading to largely useless macros. Compatibility among multiple versions of Excel are also a downfall of this method. A macro recorded in Excel 2010 may not work in Excel 2003 or older. This is most common when changing colors and formatting of cells.
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.
==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.
==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".Newcomer, Joseph M.; "Faking DDE with Private Servers", Dr. Dobb's, january 1st, 1993 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. Given the view above, it is not surprising that in Vista, Microsoft no longer supports the facility.Microsoft discontinues support for network DDE
*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.How to set up RTD in Excel
Alternatively, Microsoft Query provides ODBC-based browsing within Microsoft Excel.
Use Microsoft Query to retrieve external data
== Quirks ==
Other errors specific to Excel include misleading statistics functions, mod function errors, date limitations and the Excel 2007 error.Fix of display error for a number from 65535.99999999995 to 65536 
===Statistical functions===
The accuracy and convenience of statistical tools in Excel has been criticized,
 as mishandling missing data, as returning incorrect values due to inept handling of round-off and large numbers, as only selectively updating calculations on a spreadsheet when some cell values are changed, and as having a limited set of statistical tools. Microsoft has announced some of these issues are addressed in Excel 2010.
Function improvements in Excel 2010 Comments are provided from readers that may illuminate some remaining problems.
=== Excel MOD function error ===
Excel has issues with modulo operations. In the case of excessively large results, Excel will return the error warning #NUM! instead of an answer.
=== Date problems ===
Excel includes January 0, 1900 and February 29, 1900, incorrectly treating 1900 as a leap year. The bug originated from Lotus 1-2-3, and was purposely implemented in Excel for the purpose of backward compatibility. This legacy has later been carried over into Office Open XML file format. Excel also does not support dates before 1900.
===Filenames===
Microsoft Excel will not open two documents with the same name and instead will display the following error:
:A document with the name '%s' is already open. You cannot open two documents with the same name, even if the documents are in different folders. To open the second document, either close the document that is currently open, or rename one of the documents.The Hindu Business Line : Trouble with macros
The reason is for calculation ambiguity with linked cells. If there is a cell ='[Book1.xlsx]Sheet1'!$G$33, and there are two books named "Book1" open, there is no way to tell which one the user means.Microsoft Excel - Why Can't I Open Two Files With the Same Name?
== Numeric precision ==
thumb|390px|Excel maintains 15 figures in its numbers, but they are not always accurate: the bottom line should be the same as the top line.
Despite the use of 15-figure precision, Excel can display many more figures (up to thirty) upon user request. But the displayed figures are not those actually used in its computations, and so, for example, the difference of two numbers may differ from the difference of their displayed values. Although such departures are usually beyond the 15th decimal, exceptions do occur, especially for very large or very small numbers. Serious errors can occur if decisions are made based upon automated comparisons of numbers (for example, using the Excel If function), as equality of two numbers can be unpredictable.
In the figure the fraction 1/9000 is displayed in Excel. Although this number has a decimal representation that is an infinite string of ones, Excel displays only the leading 15 figures. In the second line, the number one is added to the fraction, and again Excel displays only 15 figures. In the third line, one is subtracted from the sum using Excel. Because the sum in the second line has only eleven 1's after the decimal, the difference when 1 is subtracted from this displayed value is three 0's followed by a string of eleven 1's. However, the difference reported by Excel in the third line is three 0's followed by a string of thirteen 1's and two extra erroneous digits. This is because Excel calculates with about half a digit more than it displays.
Excel works with a modified 1985 version of the IEEE 754 specification.
Microsoft's overview is found at: 
 Excel's implementation involves conversions between binary and decimal representations, leading to accuracy that is on average better than one would expect from simple fifteen digit precision, but that can be worse. See the main article for details.
Besides accuracy in user computations, the question of accuracy in Excel-provided functions may be raised. Particularly in the arena of statistical functions, Excel has been criticized for sacrificing accuracy for speed of calculation.
As many calculations in Excel are executed using VBA, an additional issue is the accuracy of VBA, which varies with variable type and user-requested precision.
== History ==
=== Excel 1.0, 1.5, 2.x ===
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 to Lotus 1-2-3. Microsoft released the first version of Excel for the Macintosh on 30 September 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 GUI software. Microsoft pushed its advantage with regular new releases, every two years or so.
Early in 1993 Excel became the target of a trademark lawsuit by another company already selling a software package named "Excel" in the finance industry. As the result of the dispute Microsoft had to refer to the program as "Microsoft Excel" in all of its formal press releases and legal documents. However, over time this practice has been ignored, and Microsoft cleared up the issue permanently when they purchased the trademark of the other program. Microsoft also encouraged the use of the letters XL as shorthand for the program; while this is no longer common, the program's icon on Windows (before Excel 2013) still consists of a stylized combination of the two letters, and the file extension of the default Excel format is .xls (.xlsx in newer versions). 
Excel offers many user interface tweaks over the earliest electronic spreadsheets; however, the essence remains the same as in the original spreadsheet software, VisiCalc: the program displays cells organized in rows and columns, and each cell may contain data or a formula, with relative or absolute references to other cells.
Excel became the first spreadsheet to allow the user to define the appearance of spreadsheets (fonts, character attributes and cell appearance). It also introduced intelligent cell recomputation, where only cells dependent on the cell being modified are updated (previous spreadsheet programs recomputed everything all the time or waited for a specific user command). Excel has extensive graphing capabilities, and enables users to perform mail merge.
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 has been discontinued. All versions of Excel, including Excel 2010 are capable of running an XLM macro, though Microsoft discourages their use.
=== Excel 5.0 ===
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===
Internal rewrite to 32 bits. Almost no external changes, but faster and more stable.
===Excel 97===
Major upgrade. 
Introduced the paper clip office assistant.
Standard VBA used instead of internal Excel Basic. Includes now removed Natural Language labels.
===Excel 2000===
Minor upgrade. Clipboard can hold multiple objects at once. The Office Assistant, whose frequent unsolicited appearance in Excel 97 had annoyed many users, became less intrusive.
===Excel XP===
Released about 2001. Very minor enhancements.
===Excel 2003===
Minor enhancements, most significant being the new Tables.
===Excel 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 is different from what users are used to, but the number of mouse-clicks needed to reach a given functionality is generally fewer (e.g., removing gridlines only required two mouse-clicks instead of five). However, most business users agree that the replacement of the straightforward menu system with the more convoluted ribbon dramatically reduces productivity.
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. Other features included an improved management of named variables through the Name Manager, and much improved flexibility in formatting graphs, which now allow (x, y) coordinate labeling and lines of arbitrary weight. Several improvements to pivot tables were introduced. 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===
Minor enhancements,What's New in Excel 2010 inlcuding the following:
* 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===
A lot of new tools have been included in this release:
* FlashFill
* PowerView
* PowerPivot
* Timeline Slicer
* Windows App
* Inquire
* 50 new functions
== Versions ==
=== Microsoft Windows ===
* 1987 Excel 2.0 for Windows
* 1990 Excel 3.0
* 1992 Excel 4.0
* 1993 Excel 5.0 (Office 4.2 & 4.3, also a 32-bit version for Windows NT only on the x86, PowerPC, Alpha, and MIPS architectures) This version of Excel includes a DOOM-like game as an Easter Egg.
* 1995 Excel for Windows 95 (version 7.0) included in Office 95
* 1997 Excel 97 (version 8.0) included in Office 97 (for x86 and Alpha). This version of Excel includes a flight simulator as an Easter Egg.
* 1999 Excel 2000 (version 9.0) included in Office 2000
* 2001 Excel 2002 (version 10) included in Office XP
* 2003 Office Excel 2003 (version 11) included in Office 2003
* 2007 Office Excel 2007 (version 12) included in Office 2007
* 2010 Excel 2010 (version 14) included in Office 2010
* 2013 Excel 2013 (version 15) included in Office 2013
*Note: No MS-DOS version of Excel 1.0 for Windows ever existed: the Windows version originated at the time the Mac version was up to 2.0.
*Note: There is no Excel 6.0, because the Windows 95 version was launched with Word 7. All the Office 95 & Office 4.X products have OLE 2 capacity — moving data automatically from various programs — and Excel 7 would show that it was contemporary with Word 7.
:Note: Version number 13 was skipped due to superstition.
=== 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
== 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 ==
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.
===XML Spreadsheet===
The XML Spreadsheet format introduced in Excel 2002 is a simple, XML based format missing some more advanced features like storage of VBA macros. Though the intended file extension for this format is .xml, the program also correctly handles XML files with .xls extension. This feature is widely used by third-party applications (e.g. MySQL Query Browser) to offer "export to Excel" capabilities without implementing binary file format. The following example will be correctly opened by Excel if saved either as Book1.xml or Book1.xls:
<?xml version="1.0"?>
<Workbook xmlns="urn:schemas-microsoft-com:office:spreadsheet"
 xmlns:o="urn:schemas-microsoft-com:office:office"
 xmlns:x="urn:schemas-microsoft-com:office:excel"
 xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet"
 xmlns:html="http://www.w3.org/TR/REC-html40">
 <Worksheet ss:Name="Sheet1">
 <Table ss:ExpandedColumnCount="2" ss:ExpandedRowCount="2" x:FullColumns="1"
 x:FullRows="1">
 <Row>
 <Cell><Data ss:Type="String">Name</Data></Cell>
 <Cell><Data ss:Type="String">Example</Data></Cell>
 </Row>
 <Row>
 <Cell><Data ss:Type="String">Value</Data></Cell>
 <Cell><Data ss:Type="Number">123</Data></Cell>
 </Row>
 </Table>
 </Worksheet>
</Workbook>
=== Standard file-extensions ===
Format 	Extension	Description
Spreadsheet 	.xls 	Main spreadsheet format which holds data in worksheets, charts, and macros
Add-in (VBA)	.xla 	Adds custom functionality; written in VBA
Toolbar 	.xlb 	The file extension where Microsoft Excel custom toolbar settings are stored.
Chart 	.xlc 	A chart created with data from a Microsoft Excel spreadsheet that only saves the chart. To save the chart and spreadsheet save as .XLS. XLC is not supported in Excel 2007 or in any newer versions of Excel.
Dialog 	.xld 	Used in older versions of Excel.
Archive 	.xlk 	A backup of an Excel Spreadsheet
Add-in (DLL)	.xll 	Adds custom functionality; written in C++/C, Visual Basic, Fortran, etc. and compiled in to a special dynamic-link library
Macro 	.xlm 	A macro is created by the user or pre-installed with Excel.
Template 	.xlt 	A pre-formatted spreadsheet created by the user or by Microsoft Excel.
Module 	.xlv 	A module is written in VBA (Visual Basic for Applications) for Microsoft Excel
Library 	.DLL 	Code written in VBA may access functions in a DLL, typically this is used to access the Windows API
Workspace 	.xlw 	Arrangement of the windows of multiple Workbooks
=== Office Open XML ===
Microsoft Excel 2007, along with the other products in the Microsoft Office 2007 suite, introduced new file formats. The first of these (.xlsx) is defined in the Office Open XML (OOXML) specification.
The new Excel 2007 formats are:
New Excel 2007 formats
Format 	Extension	Description
Excel Workbook 	.xlsx 	The default Excel 2007 workbook format. In reality a ZIP compressed archive with a directory structure of XML text documents. Functions as the primary replacement for the former binary .xls format, although it does not support Excel macros for security reasons.
Excel Macro-enabled Workbook	.xlsm 	As Excel Workbook, but with macro support.
Excel Binary Workbook 	.xlsb 	As Excel Macro-enabled Workbook, but storing information in binary form rather than XML documents for opening and saving documents more quickly and efficiently. Intended especially for very large documents with tens of thousands of rows, and/or several hundreds of columns.
Excel Macro-enabled Template	.xltm 	A template document that forms a basis for actual workbooks, with macro support. The replacement for the old .xlt format.
Excel Add-in 	.xlam 	Excel add-in to add extra functionality and tools. Inherent macro support because of the file purpose.
Excel 2010 continues with these new formats.
==Password protection==
Microsoft Excel protection offers several types of passwords:
* password to open a document 
* password to modify a document 
* password to unprotect worksheet
* password to protect workbook 
* password to protect the sharing workbook 
All passwords except password to open a document can be removed instantly regardless of Microsoft Excel version used to create the document. These types of passwords are used primarily for shared work on a document. Such password-protected documents are not encrypted, and a data sources from a set password is saved in a document’s header. Password to protect workbook is an exception – when it is set, a document is encrypted with the standard password “VelvetSweatshop”, but since it is known to public, it actually does not add any extra protection to the document. The only type of password that can prevent a trespasser from gaining access to a document is password to open a document. The cryptographic strength of this kind of protection depends strongly on the Microsoft Excel version that was used to create the document.
 
In Microsoft Excel 95 and earlier versions, password to open is converted to a 16-bit key that can be instantly cracked. In Excel 97/2000 the password is converted to a 40-bit key, which can also be cracked very quickly using modern equipment. The success rate of this operation is 100%. As regards services which use rainbow tables (e.g. Password-Find), it takes up to several seconds to remove protection. In addition, password-cracking programs can brute-force attack passwords at a rate of hundreds of thousands of passwords a second, which not only lets them decrypt a document, but also find the original password. 
In Excel 2003/XP the state of affairs is slightly better – a user can choose any encryption algorithm that is available in the system (see Cryptographic Service Provider). Due to the CSP, an Excel file can't be decrypted, and thus the password to open can't be removed, though the brute-force attack speed remains quite high. Nevertheless, the older Excel 97/2000 algorithm is set by the default. Therefore, users who did not changed the default settings lack reliable protection of their documents. 
The situation changed fundamentally in Excel 2007, where the modern AES algorithm with a key of 128 bits started being used for decryption, and a 50,000-fold use of the hash function SHA1 reduced the speed of brute-force attacks down to hundreds of passwords per second. In Excel 2010, the strength of the protection by the default was increased two times thanks to the use of a 100,000-fold SHA1 to convert a password to a key.
Conclusion: Currently, reliable protection is provided only by documents saved in the Office 2007/2010 format with a strong password to open set to them.
== 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. ExcelPackage 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.
== See also ==
* Comparison of risk analysis Microsoft Excel add-ins
* Comparison of spreadsheets
* Excel Viewer
* List of spreadsheets
* Spreadmart
* Visual Basic for Applications
== References ==
==General references==
* 
* 
== External links ==
*
*Office 2010 product guide
*Interactive translation from Excel 2003 menus to 2007
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