Some types of software  

Major Categories Subcategories Examples

Systems, utilities, operations

Operating system DOS, UNIX, Mac, Windows
Programming language Fortran, LISP, Java
Security: encryption, passwording, antivirus DES, Norton, McAffee, 
Disk management:
backup, defragmentation, 
compression
DiskDoubler, etc. 
File conversion Word for word; MacLink

Numerical and Data processing

spreadsheet VisiCalc, Lotus, Excel
statistics SAS, SPSS, Minitab, JMP
charting DeltaGraph
database Dbase, Oracle, Access
simulation GPSS, Stella
Formula processing Mathematica, Maple

Visual

Drawing & drafting MacDraw, Illustrator, CorelDraw
Presentation Persuasion, PowerPoint
scanning Ofoto, plug-ins
Photo processing Photoshop
animation Macromedia Director
Image analysis NIH Image, R&D
CAD AutoCAD

Communications

e-mail Eudora, LotusNotes
Web browser Netscape, Internet Explorer
telnet NCSA telnet, hyperterminal
Dial-in Kermit, procomm
ftp, finger, ping Usually with OS
Discussion: newsreader, listserver, chat Nuntius, trn, CUSeeMe

Multimedia & publishing

Desktop publishing Pagemaker, QuarkXPress
Application authoring Hypercard, toolbook
www authoring Pagemill, FrontPage, HomeSite
typesetting TeX, Postscript

Text

Word processing MSWord, MacWrite, emacs
Text/character recognition OmniPage, Kurzweil
Voice Recognition Kurzweil
Text and Content analysis Bell Labs, R&D, ?
Full Text/ Cataloging R&D, some products
Natural Language R&D, some products

Industry specific

Scores Zillions