Goldwing Media Player is free software under the GNU General Public License, version 3. Read it, build it, change it, and share it under the same terms. The Windows installer includes VLC's playback libraries; its LICENSE-NOTICE.txt lists each bundled library and its licence.
Repository: https://github.com/playtabegg/goldwing-media-player
The exact source for the build you installed is the release tagged with the version shown in Help, About. The current one is https://github.com/playtabegg/goldwing-media-player/releases/tag/v1.0.2.
Licence text: https://www.gnu.org/licenses/gpl-3.0.html.
The installer ships a LICENSE-NOTICE.txt naming every bundled library and its licence.
