Copyrights
==========

The bulk of this code is:

  Copyright (C) 1997-2005 Jose C. Pinheiro and Douglas M. Bates
  Copyright (C) 2005-2022 The R Core Team


Some of the code contains different copyright statements.
A not-necessarily-complete list is:

src/chol.f

  Copyright (C) 1996, 1997  Robert Gentleman and Ross Ihaka

src/base.h
src/matrix.h
src/nlmefit.h

  Copyright 1999-2001 Saikat DebRoy


Authors of 'fixed sigma option' of Nov. 2015:

  Siem Heisterkamp <sh.heisterkamp@icloud.com>
  Bert van Willigen <info@vanwilligen-ict.com>
  Paul Matthias Diderichsen <pmdiderichsen@wequantify.com>  (sponsor)
  
  Copyright (C) 2015 Quantitative Solutions, a Certara company


License
=======

This software is distributed under the terms of the GNU General Public
License as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
    
A copy of the GNU General Public License version 2 is in file
share/licenses/GPL-2 in the R (source or binary) distribution
and is also available at https://www.R-project.org/Licenses/.