Funtools is a "minimal buy-in" FITS library and utility package
originally developed at the the High Energy Astrophysics Division of
SAO. Although no longer actively supported at SAO, it is still widely
used within the astronomical community, especially among X-ray astronomers.

The Funtools library provides simplified access to a wide array
of file types: standard astronomical FITS images and binary tables,
raw arrays and binary event lists, and even tables of ASCII column
data. A sophisticated region filtering library (compatible with ds9)
filters images and tables using Boolean operations between geometric
shapes, support world coordinates, etc. Funtools also supports
advanced capabilities such as optimized data searching using index files.

Because Funtools consists of a library and a set of user programs, it
is most appropriately built from source. Funtools has been ported to
Solaris, Linux, Mac OSX (Darwin) and Windows 98/NT/2000/XP. Once the
source code tar file is retrieved, Funtools can be built and installed
easily using standard commands:

  ./mkconfigure				# generate all configure scripts
  ./configure --prefix=[installdir] 	# configuration
  make					# build the software
  make install				# install in [installdir]

See the INSTALL instructions (which are based on standard instructions
for building software using GNU configure) for more information about
building Funtools.