Type: Bitmap
    Extension: ras
      Version: 
  Compression: None, RLE
  Color Depth:
   Maintainer: Sun Microsystems
Specification:

Sun rasterfile is the native bitmap format of Sun Microsystem Unix systems.
The rasterfile format has become more wide-spread with the growing popularity
of the SunOS operating system and Sun SPARCStation family of Unix
workststaions.

Sun rasterfiles store images up to 32 bits in pixel depth and support a basic
for of run-length data compression.

The primary source of information for Sun Rasterfiles is the SunOS include
file /usr/include/rasterfile.h and the rasterfile online manual page:

  Sun Microsystems, rasterfile (5), Sun OS 4.0 Programmer's Manual, 1990.

The following jounal article is devoted to the Sun rasterfile:

  McGee, Format for Byte-Encoded Rasterfiles, Sun-Spots Digest, Volume 6,
  Issue 84.

And several books on graphics file formats also feature the rasterfile format.