Wikipedia
GW-BASIC is a dialect of the BASIC programming language developed by Microsoft from BASICA, originally for Compaq. It is otherwise identical to Microsoft/ IBM BASICA, but is a fully self-contained executable and does not need the ROM BASIC. It was bundled with MS-DOS operating systems on IBM PC compatibles by Microsoft. Microsoft also sold a BASIC compiler, BASCOM, compatible with GW-BASIC, for programs needing more speed. The language is suitable for simple games, business programs and the like. Since it was included with most versions of MS-DOS, it was also a low cost way for many would-be programmers to learn the fundamentals of computer programming. With the release of MS-DOS 5.0, GW-BASIC's place was eventually taken by QBasic, the interpreter part of the separately available QuickBASIC compiler.