Appropedia
appropedia.org ↗The sustainability wiki, with how-tos and project write-ups on appropriate technology, energy, water, building and development.
For makers, students, NGOs and anyone looking for low-cost, practical solutions they can reuse.
Why it’s listed
Run by the Appropedia Foundation, a California non-profit with 501(c)(3) status1. Content is CC BY-SA 4.0; 24,735 articles and edits on 13 October 2026 [Appropedia API siteinfo and recent changes].
The trade-off
Quality varies page to page, like any open wiki; 119 active users at the time we checked [Appropedia API].
Price
Free.
