Document

General and multi-function

 * Google Document (.gdoc)
 * iWork (Apple; used for Pages, Numbers, and Keynote)
 * Microsoft Compound File (OLE Compound Document)
 * Microsoft Office File Format Specifications
 * OpenDocument (ODF; OASIS)
 * UOF (Chinese office document format)

Collaboration

 * Microsoft OneNote (ONE, ONEPKG)

Desktop Publishing

 * Impression
 * Microsoft Publisher (.pub)
 * PUZ (archived "Pack and Go" file)
 * PageMaker (originally from Aldus, later Adobe)
 * PageMagic (.dtp)
 * Serif PagePlus (.ppp)
 * The Print Shop (Broderbund)
 * Timeworks Publisher (also released as Publish It!) (.dtp)

Document Processors
(similar to word processors and desktop publishing but designed particularly for building structured documents such as technical documentation)


 * FrameMaker

Document storage/exchange formats (non-program-specific)

 * AFP (Advanced Format Printing)
 * CSV (Comma Separated Values)
 * Data Interchange Format (DIF)
 * DjVu
 * OpenXPS
 * PDF (Portable Document Format)
 * PostScript
 * RTF (Rich Text Format)
 * RTFD (Rich Text Format Directory)
 * SYLK (Symbolic Link)
 * TXT (Un-structured text document)

Presentation

 * Keynote (Apple iWork/iCloud)
 * OpenDocument
 * OpenDocument Presentation (ODP)
 * OpenDocument Presentation Template (OTP)
 * PmDraw
 * PowerPoint
 * PPS (PowerPoint slide show- autoplay)
 * PPSM (PowerPoint macro-enabled slide show)
 * PPSX (PowerPoint slide show, XML format- autoplay)
 * POT (PowerPoint template)
 * POTM (PowerPoint macro-enabled template)
 * POTX (PowerPoint template, XML format)
 * PPT (PowerPoint presentation)
 * PPTM (PowerPoint macro-enabled presentation)
 * PPTX (PowerPoint presentation, XML format)
 * STI (OpenOffice.org 1.0 presentation template)
 * SXI (StarOffice / OpenOffice.org)

Spreadsheet

 * Ability Spreadsheet (.aws, .ast)
 * Excel
 * SpreadsheetML (XML format preceding later XLSX format)
 * XLS (Excel spreadsheet format)
 * XLSB (Excel binary workbook)
 * XLSM (Excel macro-enabled spreadsheet format)
 * XLSX (Excel spreadsheet format, XML version)
 * XLT (Excel template)
 * XLTM (Excel macro-enabled template)
 * XLTX (Excel template, XML version)
 * Gnumeric (.gnumeric, .gnm)
 * Google Sheet (.gsheet)
 * Lotus 1-2-3 (.wks, .wk1, .wk2, .wk3, .wk4)
 * Lotus Symphony
 * Microsoft Works spreadsheet (.wks)
 * Mouse Calc (Apple II)
 * MultiPlan (early Microsoft spreadsheet)
 * Numbers (Apple iWork/iCloud)
 * OpenDocument
 * OpenDocument Spreadsheet
 * OpenDocument Spreadsheet Template
 * OpenOffice.org
 * SXC (OpenOffice.org 1.0 Spreadsheet)
 * STC (OpenOffice.org 1.0 Spreadsheet Template)
 * pfs:Plan
 * Quattro Pro
 * SDC (StarOffice spreadsheet)
 * SuperCalc 3
 * VisiCalc

(or you can just do a spreadsheet with pen and paper)

Word Processor

 * Ability Write (.aww, .awp)
 * AbiWord (.abw)
 * AppleWorks
 * Bank Street Writer
 * ChiWriter (.chi)
 * ClarisWorks (Mac)
 * Cut & Paste (Electronic Arts Home Management Software)
 * EasiWriter / TechWriter (Word processor file format)
 * Easywriter
 * The Electric Pencil (word processor for 8080/Z-80 machines, and later IBM PC)
 * HWP (Hancom Word, Korean)
 * IBM Displaywriter (dedicated word processing machine)
 * IBM Writing Assistant (.iwa)
 * JOT (Juggler Of Text; experimental word processor by Ted Nelson c. 1980)
 * Kingsoft Office (.wps, .wpt)
 * Locoscript
 * LWP (Lotus WordPro Document)
 * MacWrite
 * Magic Window
 * MCW
 * Microsoft Word
 * DOC (Word document)
 * DOCM (Word macro-enabled document)
 * DOCX (Word document, XML format)
 * DOT (Word template)
 * DOTM (Word macro-enabled template)
 * DOTX (Word template, XML format)
 * WordProcessingML (XML format preceding later DOCX one)
 * Microsoft Works word processor document (.wps, .wpt)
 * Microsoft Write (.wri)
 * Mouse Word (Apple II)
 * Mousewrite (Apple II; apparently a different program from Mouse Word)
 * MultiMate Professional Word Processor (.dox, .pat)
 * OpenDocument Text (.odt)
 * OpenOffice.org
 * STW (OpenOffice.org 1.0 Text Document Template)
 * Pages (Apple iWork/iCloud)
 * PC-Write
 * pfs:Write
 * Samna Word
 * Scripsit
 * ScreenWriter II (for Apple II; formerly SuperScribe II)
 * Scrivener (.scriv)
 * Star Office Writer
 * SDW
 * SXW (Also used by OpenOffice.org)
 * TechWriter (Scientific word processor file format)
 * TI-Writer
 * Volkswriter
 * Wang (dedicated word processing machines)
 * Wang 1200 (1972; used cassette storage)
 * Wang OIS (1977; used disks)
 * WordPerfect
 * WordStar
 * WordStar 2000

Other

 * 602
 * ACL
 * ANS
 * ASC
 * CCF
 * CWK
 * EGT
 * FDX
 * FTM
 * FTX
 * HWPML
 * LWP
 * MBP
 * NB
 * NBP
 * ODM
 * OMM
 * OTT
 * P-touch Editor Label (.lbt, .lbx)
 * PAP
 * PDAX
 * QUOX
 * RPT
 * UOML
 * VIA
 * WRD
 * WRF

See also Markup

Links

 * CVs and File Extensions
 * Trustworthiness of Information by File Extension (xkcd comic with discussion thread)
 * Text editors in Lord of the Rings
 * Sharing or collaborating with government documents (UK government proposal)
 * Four Skills That Will Turn You Into a Spreadsheet Ninja
 * Document Freedom Day: Celebrating information accessibility and raising awareness of Open Standards.
 * G-Cloud and open file formats, a cautionary tale
 * Redaction rules: How best to keep the secrets
 * Testing for encrypted Office documents