DSD-neo project contributions are licensed under the GNU General Public License v3.0 or later. See LICENSE for the full text. This does not establish permission for every incorporated component; unresolved findings are recorded in legal/status.md.

Legacy ISC-licensed portions from the original DSD author retain their notices; the full permission text is also in LICENSES/ISC.txt. An ISC identifier on a mixed-origin file is not evidence of permission for every incorporated fragment.

The D-STAR radio-header processing path (scrambler, interleaver, Viterbi decode, CRC) was rewritten in 2025 under GPL-3.0-or-later to replace prior GPL-2.0-only contributions.

Third-party and upstream-derived code retains original notices in-place. Vendored ezpwd Reed-Solomon contains GPL-3.0-or-later/LGPL components (see src/third_party/ezpwd/ and src/third_party/ezpwd/lesser.txt). PFFFT is downloaded from the pinned arancormonk/pffft fork; its license and backend notices are installed as share/doc/dsd-neo/licenses/pffft-LICENSE.txt and pffft-NOTICES.txt. The TEA1/TEA2/TEA3 keystream generators are downloaded from the pinned MidnightBlueLabs/TETRA_crypto revision; their Apache-2.0 license is installed as share/doc/dsd-neo/licenses/tetra_crypto-LICENSE.txt. Additional embedded provenance-bearing files are summarized in THIRD_PARTY.md.

Some source files currently contain SPDX identifiers together with more specific embedded provenance or license comments inherited from upstream material. Until those headers are reconciled, consult the per-file notices and THIRD_PARTY.md for file-specific attribution and license context. Installed third-party license texts are shipped under share/doc/dsd-neo/licenses/.