since 1985 (earliest usage recorded on this site was 1986)
Microsoft QuickBASIC (also QB or incorrectly, "QBasic", which is a different system) is an Integrated Development Environment (or IDE) and compiler for the BASIC programming language that was developed by Microsoft.
QuickBASIC runs mainly on DOS, though there was a short-lived version for Mac OS. It is loosely based on GW-BASIC but adds user-defined types, improved programming structures, better graphics and disk support and a compiler in addition to the interpreter. Microsoft marketed QuickBASIC as the introductory level for their BASIC Professional Development System.