Operating system
    Database management system
    Communications monitors

System support

    Utilities
    Librarian
    Performance monitor
    Job accounting

System development

    Programming languages
        Compilers
        Interpreters
        Assemblers
    Application generators
    Fourth-generation languages

Application Software

General-purpose application software

    Spreadsheet
    Word processing
    Graphics
    Statistics packages
    Decision support software

Specific-purpose application software