https://mwmbl.org/ has a custom index of user-submitted domains and user-curated results but it’s not suitable for daily use yet.

OpenStreetMap and Internet Archive because they are operating with a small budget (as opposed to Wikipedia).

#!/bin/sh
# Select a file with fzf from a database sorted by frecency and open it using
# xdg-open. frece can be found at https://github.com/YodaEmbedding/frece

DB_FILE=${FRECE_FILES_DB:-$HOME/.cache/frecent-files.csv}
item=$(frece print "$DB_FILE" | fzf --tiebreak=index --scheme=path)

[ -z "$item" ] && exit 1
frece increment "$DB_FILE" "$item"

xdg-open "$item"

#!/bin/sh
# Update frece database

DB_FILE=${FRECE_FILES_DB:-$HOME/.cache/frecent-files.csv}
tmp_file=$(mktemp)
fd -H . ~ > "$tmp_file"  # use ~/.fdignore file to exclude certain dirs
frece update "$DB_FILE" "$tmp_file" --purge-old
rm "$tmp_file"