FreeBASIC is a free and open source multiplatform compiler and programming language based on BASIC licensed under the GNU GPL for Microsoft Windows, protected-mode MS-DOS (DOS extender), Linux, FreeBSD and Xbox.

[2] According to its official website,[3] FreeBASIC provides syntax compatibility with programs originally written in Microsoft QuickBASIC (QB).

Unlike QuickBASIC, however, FreeBASIC is a command line only compiler, unless users manually install an external integrated development environment (IDE) of their choice.

[4] On its backend, FreeBASIC makes use of GNU Binutils in order to produce console and graphical user interface applications.

As a result, FreeBASIC combines several language dialects for maximum level of compatibility with QuickBASIC and full access to modern features.

FreeBASIC provides built-in, QuickBASIC compatible graphics support through FBgfx, which is automatically included into programs that make a call to the SCREEN command.