Non-profit version of Squarespace.
https://support.squarespace.com/hc/en-us/articles/115015429248-Building-a-nonprofit-site
Content Management System · Non Profit
Get access to data on 48,192 websites that are Squarespace Non-Profit Customers. We know of 41,865 live websites using Squarespace Non-Profit and an additional 6,327 sites that used Squarespace Non-Profit historically and 30,892 websites in the United States.
Get a list of 48,192 websites using Squarespace Non-Profit which includes location information, hosting data, contact details, 41,865 currently live websites and an additional 20,802 domains that redirect to sites in this list. 6,327 sites that used this technology previously and 30,892 websites in the United States currently using Squarespace Non-Profit.