[GIMP] GNU Image Manipulation Program

GBR

The .gbr ("gimp brush") format is used for ordinary and color brushes. You can convert many other types of images, including many brushes used by other programs, into GIMP brushes by opening them in GIMP and saving them with file names ending in .gbr. This brings up a dialog box in which you can set the default Spacing for the brush. A more complete description of the GBR file format can be found in the file gbr.txt in the devel-docs directory of the GIMP source distribution.
GIH

The .gih ("gimp image hose") format is used for animated brushes. These brushes are constructed from images containing multiple layers: each layer may contain multiple brush-shapes, arranged in a grid. When you save an image as a .gih file, a dialog comes up that allows you to describe the format of the brush. Look at The GIH dialog box for more information about the dialog. The GIH format is rather complicated: a complete description can be found in the file gih.txt in the devel-docs directory of the GIMP source distribution.
VBR

The .vbr format is used for parametric brushes, i. e., brushes created using the Brush Editor. There is really no other meaningful way of obtaining files in this format.