The Quartet package as a whole is copyright (c) Martin R. Smith
<martin.smith@durham.ac.uk> and is distributed under the terms of the
GNU General Public License version 2 or later (GPL >= 2); see the file
LICENSE or https://www.gnu.org/licenses/gpl-2.0.html .

The package bundles two third-party C/C++ codebases, described below.
Each has been modified by Martin R. Smith for R integration, portability,
and memory-management fixes.

-------------------------------------------------------------------------------
Component A: tqDist
-------------------------------------------------------------------------------

Source files (within src/):
  AbstractDistanceCalculator.cpp, AbstractDistanceCalculator.h,
  counting_linked_list.h, counting_linked_list_num_only.h,
  EdgeParser.cpp, edge_parser.h,
  HDT.cpp, HDTCountingCCToC.cpp, HDTCountingCTransform.cpp,
  HDTCountingG.cpp, HDTCountingIGToC.cpp, HDTCountingLeaf.cpp,
  HDTFactory.cpp, HDTListUtils.cpp,
  hdt.h, hdt_factory.h,
  int_stuff.cpp, int_stuff.h,
  memory_allocator.h,
  NewickParser.cpp, newick_parser.h,
  quartet_calc.h,
  QuartetDistanceCalculator.cpp, QuartetDistanceCalculator.h,
  rooted_tree.h, RootedTree.cpp, RootedTreeFactory.cpp, rooted_tree_factory.h,
  templated_linked_list.h,
  triplet_calc.h,
  TripletDistanceCalculator.cpp, TripletDistanceCalculator.h,
  unrooted_tree.h,
  util.h,
  rQuartetDist.cpp, rTripletDist.cpp

Original authors / copyright holders:
  Andreas Sand, Morten K. Holt, Jens Johansen,
  Gerth Stølting Brodal, Thomas Mailund, Christian N. S. Pedersen

Reference:
  Sand A, Holt MK, Johansen J, Brodal GS, Mailund T, Pedersen CNS (2014).
  "tqDist: a library for computing the quartet and triplet distances between
  binary or general trees."  Bioinformatics 30(14):2079-2080.
  doi:10.1093/bioinformatics/btu157

Upstream source:
  http://birc.au.dk/software/tqDist

Licence:
  GNU Lesser General Public License (LGPL).  LGPL is compatible with and
  is redistributed here under GPL (>= 2).

-------------------------------------------------------------------------------
Component B: CPDT / cpdt-dist
-------------------------------------------------------------------------------

Source files (within src/):
  cpdt-dist.cpp  (R/Rcpp glue written by Martin R. Smith, after Rajaby)
  cpdt-dist/bit.h
  cpdt-dist/cpdt-dist.h
  cpdt-dist/cpdt-dist-bin.h
  cpdt-dist/nex_parse.h
  cpdt-dist/tree.h
  cpdt-dist/tree_parse.h
  cpdt-dist/treenode.h
  cpdt-dist/utils.h

Original authors / copyright holders:
  Jesper Jansson, Ramesh Rajaby

Reference:
  Jansson J, Rajaby R (2017).
  "A more practical algorithm for the rooted triplet distance."
  Journal of Computational Biology 24(2):106-126.
  doi:10.1089/cmb.2016.0185

Upstream source:
  https://github.com/Mesh89/cpdt-dist

Licence:
  The upstream repository carries no explicit licence.  The authors,
  Jesper Jansson and Ramesh Rajaby, have granted the Quartet maintainer
  (Martin R. Smith) permission to incorporate and redistribute this code
  under the GNU General Public License version 2 or later (GPL >= 2),
  the licence that governs the Quartet package as a whole.