Grav - The modern open source flat-file CMS
Notpla - Cheaper than plastic, and edible! Reduce single use plastic
WonderCMS - WonderCMS is the smallest flat file CMS. Completely free, open source, privacy oriented for over 12 years.
Eticaly - Find fashion brands that fit your values
HTMLy - HTMLy is an open source databaseless blogging platform. A Flat-File Blog and Flat-File CMS written in PHP prioritizes simplicity and speed.
Ethical Resources - Huge repository of ethical alternatives to mainstream stuff