Welcome to FreeBASIC

FreeBASIC is a free/open source (GPL), BASIC compiler for Microsoft Windows, DOS and Linux.

When used in its "QB" language mode, FreeBASIC provides a high level of support for programs written for QuickBASIC. Many programs written for QuickBASIC will compile and run in this mode with no changes needed. However, for compilation in the FreeBASIC default language mode, most substantial programs will require changes.

  • Compatible
  • Powerful
  • Expressive
  • 100% Free Software
Simple Example showing procedures.
  1. function AddNumbers( a as integer, b as integer ) as integer
  2.         return a + b
  3. end function
  5. sub hello( )
  6.         print "hello"
  7. end sub
  9. declare sub myprint( num as integer )
  11. 'Code outside any procedures is the main part of the program
  12. hello( )
  13. print AddNumbers( 1, 1 )
  14. myprint 5
  16. sub myprint( num as integer )
  17.         print num
  18. end sub

FreeBASIC is a self-hosting compiler which makes use of the GNU binutils programming tools as backends and can produce console, graphical/GUI executables, dynamic and static libraries. FreeBASIC fully supports the use of C libraries and has partial C++ library support. This lets programmers use and create libraries for C and many other languages. It supports a C style preprocessor, capable of multiline macros, conditional compiling and file inclusion.

FreeBASIC has been rated close in speed with mainstream tools, such as GCC.

More about FreeBASIC

The FreeBASIC project is a set of cross-platform development tools, consisting of a compiler, GNU-based assembler, linker and archiver, and supporting runtime libraries, including a software-based graphics library. The compiler, fbc, currently supports building for i386-based architectures on the DOS, Linux, Windows and Xbox platforms. The project also contains thin bindings (header files) to some popular 3rd party libraries such as the C runtime library, Allegro, SDL, OpenGL, GTK+, the Windows API and many others, as well as example programs for many of these libraries.

FreeBASIC is a high-level programming language supporting procedural, object-orientated and meta-programming paradigms, with a syntax compatible to Microsoft QuickBASIC. In fact, the FreeBASIC project originally began as an attempt to create a code-compatible, free alternative to Microsoft QuickBASIC, but it has since grown into a powerful development tool. FreeBASIC can be seen to extend the capabilities of Microsoft QuickBASIC in a number of ways, supporting more data types, language constructs, programming styles, and modern platforms and APIs.

Any type of program can be written with FreeBASIC, see our Gallery of Applications for some notable examples.

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