The texture files in this folder are simply small PICT files, and they are provided in here as an example. They can be projected onto RenderBoy objects to give them a much more realistic appearance.
A more complete set of textures is located in the "RenderBoy Libraries" folder. If you do not have the RenderBoy Libraries, you can download them from the official RenderBoy web site:
http://members.aol.com/luv2render
If you installed RenderBoy from a CD-ROM, the RenderBoy libraries should also be available on the CD.