diff --git a/grouper/groups.sh b/grouper/groups.sh
new file mode 100644
index 0000000..bce2ff1
--- /dev/null
+++ b/grouper/groups.sh
@@ -0,0 +1,65 @@
+#!/usr/bin/env ash
+
+. /home/zgrep/offtopiabday/happybot/common.sh
+
+base="/home/zgrep/offtopiabday/grouper/groups"
+
+irc | while read -r n m; do
+	m="$(var "$m" | grep -v "^$zwsp")"
+	if hreg '^happybot[:,] groups? (add|del|list|rm) @?([a-z0-9][a-z0-9\-_]*)$' "$m"; then
+		group="$(m 2)"
+		file="$base/$group"
+		if [ "$(m 1)" == "add" ]; then
+			if [ ! -e "$file" ]; then
+				touch "$file"
+			elif grep -F -i -e "$n" "$file"; then
+				var "$n: You're already part of @$group." | zwsp | say
+				continue
+			fi
+			var "$n" >> "$file"
+			var "$n: Added you to $group." | zwsp | say
+		elif [ "$(m 1)" == "list" ]; then
+			if [ -e "$file" ]; then
+				var "$n: $(cat "$file" | sed "s/./&$zwsp/" | tr '\n' ',' | sed 's/,$//;s/,/, /g')" | zwsp | say
+			else
+				var "$n: Nobody is in @$group." | zwsp | say
+			fi
+		else
+			if [ -e "$file" ]; then
+				new="$(grep -F -i -v -e "$n" "$file")"
+				if [ -z "$new" ]; then
+					rm "$file"
+				else
+					var "$new" > "$file"
+				fi
+				var "$n: You have been removed from @$group." | zwsp | say
+			else
+				var "$n: You are not in group @$group." | zwsp | say
+			fi
+		fi
+	elif hreg '^happybot[:,] groups? list$' "$m"; then
+		var "$n: $(ls -1 "$base" | sed 's/^/@/' | tr '\n' ',' | sed 's/,$//;s/,/, /g')" | zwsp | say
+	elif hreg '^happybot[:,] groups?(?:$| .*$)' "$m"; then
+		var "$n: Usage: groups add|del|list @[a-z0-9][a-z0-9_-]*" | zwsp | say
+	elif reg ' cc ([^ ,]+(?:, ?[^ ,]+)*)' "$m"; then
+		grep='grep -o -F -i '"$(ls -1 "$base" | sed "s/^/-e '@/;s/\$/'/" | tr '\n' ' ')"
+		groups="$(var "$(m 1)" | sed 's/,/ /g;s/  / /g' | tr ' ' '\n' | eval "$grep" | sed 's/^@//')"
+		if [ ! -z "$groups" ]; then
+			new="$m"
+			for group in $groups; do
+				people="$(cat "$base/$group" | grep -v -F -e "$n" | tr '\n' ',' | sed 's/,$//;s/,/, /g')"
+				if [ ! -z "$people" ]; then
+					new="$(var "$new" | sed 's/ cc \(.*\)@'"$group"'/ cc \1'"$people"'/')"
+				fi
+			done
+			if [ "$m" == "$new" ]; then
+				continue
+			fi
+			if [ "${#new}" -gt 400 ]; then
+				new="[…] $(var "$new" | sed 's/.*\(.\{400\}\)$/\1/')"
+			fi
+			new="<$(var "$n" | sed "s/./&$zwsp/")> $new"
+			var "$new" | zwsp | say
+		fi
+	fi
+done