The default file extension for a saved Microsoft Excel 2007 workbook is XLSX. However, the "Save As" command can convert a worksheet to other file types such as text, comma delimited files and HTML Web formats. It also has the ability to convert a spreadsheet into a format that is accessible by other spreadsheet applications. Excel can also open documents with a variety of extensions and convert them into a standard Excel spreadsheet format.
Older versions of Excel cannot access and process an Excel spreadsheet saved in the new XLSX format. To allow a user with an older version of Excel to open an Excel 2007 spreadsheet, use Excel's "Save As" command to convert a 2007 spreadsheet into the XLS format used by Excel versions developed between 1997 and 2003.
Other new extensions in Excel 2007 include the XLSM extension for spreadsheets containing automatic macros and VBA (Visual Basic Application) code. The XLSB extension is a binary format developed by Microsoft to enable faster loading of a spreadsheet. Excel 2007 can also save template files using the Excel 2007 extension XLTX, which is the macro-enabled extension XLTM and the older XLT extension.
Spreadsheet Sharing Extensions
To make Excel spreadsheets more versatile between users with different spreadsheet and database application programs, Microsoft enabled Excel to convert files into formats used by other spreadsheet programs. When saved in the SLK (SYlmbolic Link) extension, Excel converts a spreadsheet into an ANSI character file that is easy for other applications to process. The other format for exchanging spreadsheets between other applications is the DIF (Data Interchange Format) extension.
Many applications used in inventory processing and other retail functions use comma delimited text files to process data. A CVS, or comma delimited file, is a text file where commas separate individual data fields. Some companies use Excel to input data from such procedures as an inventory count, and then use the "Save As" function to convert the file to a CVS format. Excel also has the ability to convert a spreadsheet to a standard text file with the TXT extension.
Microsoft included the ability of Excel to convert a spreadsheet into a format for Internet use. These formats include the MHT and MHTML extensions used for MIME HyperText Markup Language files also known as single Web page formats. Excel also has the ability to save a spreadsheet in a standard HyperText Markup Language used in Web page development with the HTML or HTM extensions.