FreeBASIC

FreeBASIC, althought is a new compiler (the first version was released the 30 of November 2004), it is not a 'new' BASIC language. The user must not learn anything new than DOS Basic. FreeBASIC is compatible with QBasic and QuickBasic but the author states that 'compatibility doesn't mean you can compile a source-code made for QuickBASIC and hope it will run fine'. The language itself contains only a small number of keywords: all functions are implemented as libraries. FreeBASIC does not have any new intrinsic routine, like MSGBOX for example, so there's no variable clashes with old code. The language supports dynamic and static arrays up to 2GB, with unlimited number of dimensions, redim preserve; inline Assembly; reference to variables is by name; it may create OBJ, LIB, DLL, console and GUI EXEs. While FreeBASIC isn't an optimizing compiler, it does many kinds of optimizations to generate the fastest possible code on x86 CPU's, not losing against other BASIC alternatives. The package does not come with an IDE but a third-party IDE may be downloaded from the Links section.

Web site: http://www.freebasic.net/