The file LICENSE has placeholders that CRAN substitutes into its
template.  optbin has a BSD 3-clause license; if you've gotten a
copy outside of CRAN the full text is below.

Copyright (c) 2020, Primordial Machine Vision Systems, Inc.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

    Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.

    Redistributions in binary form must reproduce the above copyright
    notice, this list of conditions and the following disclaimer in
    the documentation and/or other materials provided with the
    distribution.

    Neither the name of Primordial Machine Vision Systems, Inc. nor
    the names of its contributors may be used to endorse or promote
    products derived from this software without specific prior written
    permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.


The source directory contains the file pcg-variants.h, the PCG random
number generator.  It is taken unmodified from the pcg-c-0.94.zip
distribution found on www.pcg-random.org, and used in sigtests.c for
the excursion test.  The file is under the Apache Version 2 license.
You can use the stock RNG by compiling with -DNO_PCGRNG.

The data directory contains the file kirkwood.rda, a small subset of the
asteroid ephemeris maintained by Lowell Observatory.  The help page
contains references to the web site, papers, and required acknowledgement
of funding sources.