Microsoft QuickBASIC is a descendant of the BASIC programming language developed by the Microsoft Corporation for use with the MSDOS Operating System. The shortened name is correctly QB, and incorrectly QBASIC. It bases loosely on Microsoft GW-BASIC but added user-defined types, improved programming structures, better graphics and disk support and a compiler rather than an interpreter. Microsoft sold QuickBASIC as a commercial development suite. However, some versions of MS-DOS included a limited version of it as QBASIC. The limited version lacked several functions, could only handle files of a limited size, and was an interpreter only. QuickBasic produced no executable files.
Microsoft released the first version of QuickBASIC on 18 August 1985 stored on a single 5.25" floppy disk. QuickBASIC came with a markedly different Integrated Development Environment (IDE) from the one supplied with previous versions of BASIC. Line numbers were no longer needed since users could insert and remove lines directly via an on screen text editor.
It included Microsoft's "PC BASIC Compiler" which compiled programs into DOS executables. The editor had an interpreter built in which would run the program without leaving the editor at all. The IDE included also an option to debug the program before creating an executable file.
QuickBASIC's last version was 4.5 although there was continued development of the Professional Development System (PDS), the last release of which was version 7.1. Another name of the PDS version was QuickBASIC Extended. The successor to QuickBASIC and PDS was Visual Basic 1.0 which came in incompatible versions for both DOS and Windows. Later versions of Visual Basic did not include DOS versions as Microsoft wanted developers to concentrate on Windows applications.