GSL is copyrighted and may be distributed under the terms of the GNU
General Public License V2. 

GSL authors are:

Mark Galassi (rosalia@lanl.gov) - overall design, simulated annealing
Jim Davies (jimmyd@nis.lanl.gov) - statistics library
James Theiler (jt@nis.lanl.gov) - random number generators
Brian Gough (bjg@network-theory.co.uk) -
  FFTs, numerical integration, random number generators and
distributions,
  root finding, minimization and fitting, polynomial solvers, complex
  numbers, physical constants, permutations, vector and matrix
functions,
  histograms, statistics, ieee-utils, revised CBLAS Level 2 & 3, matrix
  decompositions and eigensystems.
Reid Priedhorsky (rp@lanl.gov) - root finding
Gerard Jungman (jungman@lanl.gov) special functions, interpolation, 
  series acceleration, ODEs, BLAS, Linear Algebra, Eigensystems,
  Hankel Transforms.
Michael Booth (booth@debian.org (email address not working)) - Monte 
  Carlo integration
Fabrice Rossi (rossi@ufrmd.dauphine.fr) - Multidimensional minimization
Simone Piccardi (piccardi@fi.infn.it) - Ntuples
Carlo Perassi (carlo@linux.it) - Additional random number generators
Dan, Ho-Jin (hjdan@sys713.kaist.ac.kr) - divided differences
interpolation
Szymon Jaroszewicz (sj@cs.umb.edu) - combinations
Nicolas Darnis (ndarnis@cvf.fr) - canonical permutation functions
Tuomo Keskitalo (tuomo.keskitalo@iki.fi) - multidimensional minimization
Ivo Alxneit (ivo.alxneit@psi.ch) - multidimensional minimization
Jason H. Stover (jason@sakla.net) - cumulative distribution functions