DragonBASIC is a BASIC programming language for the Game Boy Advance. It is used to easily write games and applications for the GBA.
DragonBASIC was a commercial product but the developer is now giving it away because it is just about abandonware.
DragonBASIC has its own Windows based editor, which is used to write the programs, and it can also compile the program to Game Boy Advance native executables (*.GBA). These files can then be run in Game Boy Advance emulators, such as VisualBoyAdavance or on the GameBoy itself using special flashable cartridges, and a link cable.
DragonBASIC has support for most of the Game Boy Advance functionality, including tile based graphics, bitmap graphics, sound, mode 7 style scrolling, and save game support.