Fonts bundled with the plugin, all under the SIL Open Font License 1.1 (https://openfontlicense.org), as packaged by Fontsource (https://fontsource.org):

Inter - Copyright The Inter Project Authors
Poppins - Copyright Indian Type Foundry
Montserrat - Copyright The Montserrat Project Authors
Playfair Display - Copyright The Playfair Display Project Authors
Lora - Copyright The Lora Project Authors
Cairo - Copyright The Cairo Project Authors
Amiri - Copyright The Amiri Project Authors

Only the Latin or Arabic subset, regular and bold, is included. The fonts are used by the layouts and can be chosen in Mosaic, Site Settings. They may be used, studied, copied and redistributed freely; they may not be sold on their own.
