Applications are computer programs that allow a user to manipulate data in specified ways. Databases, spreadsheets, word processing, page layout programs, and drawing programs are electronic versions of older business systems. Communications and networking programs are extensions of the computer as an electronic medium. Some applications even include their own languages, allowing the user to write related routines or customize use of the application. Applications were written for mainframe computer systems beginning in the 1950s. The wide variety of user-oriented applications began with the personal computer, beginning in the mid-1970s, developing along with faster processing chips, large computer memory and disk storage, and more flexible operating systems. The modern software industry began in 1975, when William Gates and Paul Allen wrote an interpreted version of the language BASIC for the first personal computer, the Altair (MITS). This made it easy and even fun to write applications...