Description: Adobe Acrobat Reader is a program that allows users to view files in Portable Document Format (PDF). PDF is a universal file format that preserves the appearance of the original document. PDF files can be easily printed but not easily modified. Several documents throughout this Web site are available in PDF. These files contain complex documents with graphs, images, and special text that cannot be presented easily through the typical Web browser. The creator of this file format, Adobe® Systems, offers a free viewer so that you can view any PDF file.
File extensions: pdf
Viewing: If you do not already have Adobe Acrobat, you can download Acrobat Reader for free* .

Description: Microsoft PowerPoint is a program for creating and viewing presentations and slide shows.
File extensions: ppt
Viewing: If you do not already have PowerPoint, you can download PowerPoint Viewer for free* .

Description: Microsoft Word is a word processing program used to create and edit text documents. Text in Word documents can be easily modified or copied for use in other applications.
File extensions: doc, rtf
Viewing: If you do not already have Word, you can download Word Viewer for free* .

Description: QuickTime is a program for viewing and listening to audio and video files (including live broadcasts).
File extensions: mov, qt, mpg, mpeg, mp3, mp4
Viewing/listening: If you do not already have QuickTime, you can download QuickTime for free* .

Description: RealPlayer is a program for viewing and listening to audio and video files (including live broadcasts).
File extensions: ra, ram, rm
Viewing/listening: If you do not already have RealPlayer, you can download RealPlayer for free* . (Select "Download Free RealPlayer" on the right side of the page.)

Description: Windows Media Player is a program for viewing and listening to audio and video files (including live broadcasts).
File extensions: asf, asx, avi, wma, wmv, wm, wpl, mpg, mpeg, mp3, mp4
Viewing/listening: If you do not already have Windows Media Player, you can download Windows Media Player for free* .

Description: Microsoft Excel is a spreadsheet program used to calculate, analyze, and store data. Text in Excel files can be easily modified or copied for use in other applications.
File extensions: xls
Viewing: If you do not already have Excel, you can download Excel Viewer for free* .

Description: WinZip and similar programs (such as PowerZip, TurboZip, ZipScan, WinConfig, and StuffIt) are used to archive and compress files so that they can be stored and distributed more efficiently.
File extensions: zip, cab
Viewing: If you do not already have a compression program such as WinZip, you can download a free 21-day trial version of WinZip* or download a similar compression program* .