QBasic is an integrated development environment (IDE) and interpreter for a variety of dialects of BASIC which are based on QuickBASIC.

[1] Like QuickBASIC, but unlike earlier versions of Microsoft BASIC, QBasic is a structured programming language, supporting constructs such as subroutines.

For its time, QBasic provided a state-of-the-art IDE, including a debugger with features such as on-the-fly expression evaluation and code modification.

Starting with Windows 2000, Microsoft no longer includes QBasic with their operating systems.

[1] QBasic has an Easter egg accessed by pressing and holding Left CTRL+Left SHIFT+Left ALT+Right CTRL+Right SHIFT+Right ALT simultaneously after running QBasic at the DOS prompt but before the title screen loads: this lists The Team of programmers.