Silicon Graphics (SGI) was a computer company that existed from 1981
to 2009. During this period, they shipped software for their
computers, sometimes on CD, and often not using the standard ISO9660
file system. These discs are instead simply hard disc images pressed
to CD. Thus, they have an SGI disk label and an EFS partition.

Most systems cannot understand this sort of disc format. This tool was
developed to allow non-SGI systems to at least be able to extract
files from such discs.