FreeBASIC - Open Source Alternative to QuickBASIC

FreeBASIC is a free and open-source BASIC compiler. It is compatible to a large extent with MS-QuickBASIC (QBASIC), but has additional features such as pointers, unsigned data types and inline-assembly.

One of the objectives of the project is operating system independence. The latest version has been released for Linux, Windows, and DOS. Development of a backend for GCC will provide support for AMD64, PCC and other architectures.

The gfxlib2 library is included in FreeBasic, which makes it possible to write graphical QBasic compatible programs. However, FreeBASIC's graphics capabilities exceed those of QBASIC. It has, for example, much higher resolutions and object-oriented extensions.

FreeBASIC is licensed under GPL and can be downloaded here.