Iconmonstr

Iconmonstr is licensed under terms published on its site: Iconmonstr license text

The site hosts thousands icons in multiple formats. These are flat icons, but the site also allows some color and styling. Custom icons can be requested.
FFHEx uses these icons in the app's welcome screen, the main window, and the primary editing dialogs.
on the main windows and the primary editors.

7za (7-zip)

The 7za standalone utility is licensed under LGPL. 7-zip License Page

The 7za standalone utility is used to handle project and assembly source archives in ZIP format.

The MIT/Expat License

Copyright 2022 Esselle Jaye

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.