Third-party notices for V-BAR

V-BAR is released under the MIT license (see LICENSE). This file lists material from other
projects that is included in this repository, and its license.

Contributor Covenant, version 2.1
  Used in:  CODE_OF_CONDUCT.md (contact address filled in)
  Source:   https://github.com/EthicalSource/contributor_covenant, commit b1b0a0f,
            content/version/2/1/code_of_conduct.md
  License:  Creative Commons Attribution 4.0 International (CC BY 4.0), the license of that
            repository at that commit
  Credit:   Organization for Ethical Source and the Contributor Covenant contributors

GRACE-FO Level-1B data, 2019-12-03
  Used in:  src/vbar/flightdata/gracefo_2019-12-03.csv (an excerpt of the GNV1B and KBR1B files,
            installed with the package), written by examples/gracefo_excerpt.py
  Source:   GRACE-FO (2019), GRACEFO_L1B_ASCII_GRAV_JPL_RL04, ver. 4, PO.DAAC, CA, USA,
            doi:10.5067/GFL1B-ASJ04
  License:  CC0, under the NASA Earthdata data use policy for NASA-led missions; no endorsement
            by NASA is implied

No third-party source code is included. Methods taken from the literature are reimplemented
and cited where they are used.

Reimplemented from MIT-licensed code, without copying it:
  KSPDG, https://github.com/mit-ll/spacegym-kspdg, v0.15.0, commit 6251ca3
    Used in:  vbar.games: the pe1 problem definition (pe1_base.py, base_envs.py), the evader
              rules of e1_envs.py to e4_envs.py, the orbits of the pe1 mission saves, and the
              module and class names of vbar.games.compat
  github.com/ARCLab-MIT/kspdg, commit a45e5c6
    Used in:  vbar.games.pursuers.ClosestApproachAgent and closest_approach, after Jason Cheng's
              arclab_mit/agents/extended_obs_agent/deterministic_agent.py and simulate.py
  License:  MIT License, Copyright (c) 2022 Massachusetts Institute of Technology (the LICENSE.txt
            of both repositories)

Dependencies are installed separately and are not redistributed with V-BAR. CI fails if any
installed dependency of the dev, onnx, plot and replay extras declares a GPL-family license or
no license; the basilisk and orekit extras are read from their package metadata by hand, below.
At the time of writing:
  numpy       BSD-3-Clause
  scipy       BSD-3-Clause
  gymnasium   MIT
  matplotlib  Matplotlib License (PSF-based), optional "plot" extra
  onnx        Apache-2.0, optional "onnx" extra
  onnxruntime MIT, optional "onnx" extra (with protobuf, BSD-3-Clause, and flatbuffers,
              Apache-2.0)
  rerun-sdk   MIT OR Apache-2.0, optional "replay" extra (with pyarrow, Apache-2.0, pillow,
              MIT-CMU, attrs, MIT, psutil, BSD-3-Clause, and typing-extensions, PSF-2.0)
  bsk         ISC, optional "basilisk" extra (Basilisk, AVS Lab, University of Colorado;
              version 2.12.1 metadata)
  orekit-jpype Apache-2.0 (package metadata: Apache Software License, version 13.1.9.0),
              optional "orekit" extra, with JPype (Apache-2.0) and the Orekit library
              (Apache-2.0)

The Orekit backend needs a Java runtime, which the user provides (JAVA_HOME). When JAVA_HOME
is not set it uses the optional package jdk4py, a JDK shipped in a Python package, if the user
has installed it. jdk4py is not a dependency of any V-BAR extra and V-BAR neither installs nor
redistributes it; its package metadata (version 25.0.2.1) declares the GNU General Public
License v2.
