Legal
Third-party notices
Last updated 23 Oct 2026
ArcturusSDR includes the following third-party software. The full licence texts are shipped with the app (Help > Third-Party Licences, and the Licenses folder installed with it), and each release's notices are on the source downloads.
| Component | Licence | How it is used |
|---|---|---|
| Qt (QtCore, QtGui, QtWidgets, QtConcurrent, QtNetwork) | LGPL-3.0 | Linked dynamically, not modified. See Source code offers. |
| Third-party code inside Qt (FreeType, HarfBuzz, libpng, libjpeg-turbo, PCRE2, zlib and others) | Each component's own (MIT, BSD, zlib, FTL, Apache-2.0 and others) | Inside the Qt libraries the macOS and Windows installers carry |
| Fraunhofer FDK AAC Codec Library for Android | Fraunhofer FDK AAC licence | Compiled in, unmodified, to decode DRM and DAB+ audio. Its source is offered free with each release. |
| SQLite | Public domain | Compiled in |
| SQLiteCpp | MIT | Compiled in |
| pocketfft | BSD-3-Clause | Compiled in |
| miniaudio | Unlicense or MIT-0 | Compiled in, for playback |
| minimp3 | CC0-1.0 | Compiled in, to decode DAB audio and play MP3 files |
| rade_c (FreeDV RADE) | BSD-2-Clause | Compiled in |
| freedv-backend (RADE text and LDPC code) | BSD-2-Clause | Compiled in |
| Opus | BSD-3-Clause | Compiled in |
| RNNoise | BSD-3-Clause | Compiled in, for the microphone's noise reduction |
| Monocypher | BSD-2-Clause or CC0-1.0 | Compiled in |
| cJSON | MIT | Compiled in, in the licensing client |
| CLAP | MIT | Its headers, in the audio plug-in host |
| VST3 plug-in interfaces | MIT | Its headers, in the audio plug-in host |
| ASIO SDK (Windows) | Steinberg's ASIO licence | Its headers, for ASIO audio devices |
| SoapySDR | BSL-1.0 | Included (macOS and Windows) and loaded at run time, for USB radios |
| SoapyHackRF and libhackrf | MIT; BSD-3-Clause | Included, for the HackRF One |
| SoapyAirspy and libairspy | MIT; BSD-3-Clause and MIT | Included, for the Airspy R2 and Mini |
| SoapyAirspyHF and libairspyhf | MIT; BSD-3-Clause | Included, for the Airspy HF+ |
| LimeSuite with SoapyLMS7 (macOS) | Apache-2.0, with BSD-3-Clause and MIT parts | Included, for LimeSDR boards |
| SoapySDRPlay3 | MIT | Included, for SDRplay radios (with SDRplay's own API, which you install) |
| pthreads4w (Windows) | Apache-2.0 | Included, for the radio libraries |
| Crashpad, mini_chromium and MPack | Apache-2.0, BSD-3-Clause, MIT | Compiled in, to write crash reports |
| zlib (Windows) | zlib licence | Compiled in, with Crashpad |
| Sparkle (macOS) | MIT, with BSD-2-Clause and zlib parts | Included, for updates |
| WinSparkle (Windows), with wxWidgets, expat, OpenSSL's libcrypto and ed25519 | MIT; wxWindows Library Licence; MIT; OpenSSL licence; zlib | Included, for updates |
| FT4 and FT8 protocol definition files | Public domain | Data only |
| Amateur Radio Country Files (cty.dat) | MIT | Data only |
| mbelib quantiser tables | ISC | Data only |
| Natural Earth coastlines | Public domain | Data only |
The Fraunhofer FDK AAC library is used under its own licence; Fraunhofer's name is not used to promote ArcturusSDR, and no fee is charged for the library.
Not included
These are used when you have them, but are not part of ArcturusSDR:
| Component | Licence | How it is used |
|---|---|---|
| libusb | LGPL-2.1 or later | Needed for USB radios. You install it yourself; ArcturusSDR loads your copy. See the help page "Installing libusb". |
| SoapyBladeRF, SoapyUHD and other SoapySDR modules | Their own | Installed by you for radios ArcturusSDR does not include a module for |
| libcurl (macOS and Linux); libsecret and libX11 (Linux) | curl licence; LGPL-2.1 or later; MIT | The system's own copies |