diff --git a/.gitignore b/.gitignore
index b7f8e7e..152e0e5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,6 @@
 *.pyc
 *~
 *.8
+/.do_built
+/.do_built.dir
+/.redo
diff --git a/Makefile b/Makefile
index 5958871..c167744 100644
--- a/Makefile
+++ b/Makefile
@@ -1,19 +1,10 @@
-PANDOC:=$(shell \
-	if pandoc </dev/null 2>/dev/null; then \
-		echo pandoc; \
-	else \
-		echo "Warning: pandoc not installed; can't generate manpages." >&2; \
-		echo '@echo Skipping: pandoc'; \
-	fi)
+all:
 
-default: all
+Makefile:
+	@
 
-all: sshuttle.8
+%: FORCE
+	+./do $@
 
-sshuttle.8: sshuttle.md
+.PHONY: FORCE
 
-%.8: %.md
-	$(PANDOC) -s -r markdown -w man -o $@ $<
-
-clean:
-	rm -f *~ */*~ .*~ */.*~ *.8 *.tmp */*.tmp *.pyc */*.pyc
diff --git a/all.do b/all.do
new file mode 100644
index 0000000..7a7f6b9
--- /dev/null
+++ b/all.do
@@ -0,0 +1,4 @@
+UI=
+[ "$(uname)" = "Darwin" ] && UI=ui-macos/all
+redo-ifchange sshuttle.8 $UI
+
diff --git a/clean.do b/clean.do
new file mode 100644
index 0000000..2baeb36
--- /dev/null
+++ b/clean.do
@@ -0,0 +1,2 @@
+redo ui-macos/clean
+rm -f *~ */*~ .*~ */.*~ *.8 *.tmp */*.tmp *.pyc */*.pyc
diff --git a/default.8.do b/default.8.do
new file mode 100644
index 0000000..6d8dc8c
--- /dev/null
+++ b/default.8.do
@@ -0,0 +1,7 @@
+exec >&2
+if pandoc </dev/null 2>/dev/null; then
+	pandoc -s -r markdown -w man -o $3 $1.md
+else
+	echo "Warning: pandoc not installed; can't generate manpages."
+	redo-always
+fi
diff --git a/do b/do
new file mode 100755
index 0000000..901e4f3
--- /dev/null
+++ b/do
@@ -0,0 +1,150 @@
+#!/bin/sh
+#
+# A minimal alternative to djb redo that doesn't support incremental builds.
+# For the full version, visit http://github.com/apenwarr/redo
+#
+# The author disclaims copyright to this source file and hereby places it in
+# the public domain. (2010 12 14)
+#
+
+# By default, no output coloring.
+GREEN=""
+BOLD=""
+PLAIN=""
+
+if [ -n "$TERM" -a "$TERM" != "dumb" ] && tty <&2 >/dev/null 2>&1; then
+	GREEN="$(printf '\033[32m')"
+	BOLD="$(printf '\033[1m')"
+	PLAIN="$(printf '\033[m')"
+fi
+
+_dirsplit()
+{
+	base=${1##*/}
+	dir=${1%$base}
+}
+
+_dirsplit "$0"
+export REDO=$(cd "${dir:-.}" && echo "$PWD/$base")
+
+DO_TOP=
+if [ -z "$DO_BUILT" ]; then
+	DO_TOP=1
+	[ -n "$*" ] || set all  # only toplevel redo has a default target
+	export DO_BUILT=$PWD/.do_built
+	: >>"$DO_BUILT"
+	echo "Removing previously built files..." >&2
+	sort -u "$DO_BUILT" | tee "$DO_BUILT.new" |
+	while read f; do printf "%s\0%s.did\0" "$f" "$f"; done |
+	xargs -0 rm -f 2>/dev/null
+	mv "$DO_BUILT.new" "$DO_BUILT"
+	DO_PATH=$DO_BUILT.dir
+	export PATH=$DO_PATH:$PATH
+	rm -rf "$DO_PATH"
+	mkdir "$DO_PATH"
+	for d in redo redo-ifchange; do
+		ln -s "$REDO" "$DO_PATH/$d";
+	done
+	[ -e /bin/true ] && TRUE=/bin/true || TRUE=/usr/bin/true
+	for d in redo-ifcreate redo-stamp redo-always; do 
+		ln -s $TRUE "$DO_PATH/$d";
+	done
+fi
+
+
+_find_dofile_pwd()
+{
+	DOFILE=default.$1.do
+	while :; do
+		DOFILE=default.${DOFILE#default.*.}
+		[ -e "$DOFILE" -o "$DOFILE" = default.do ] && break
+	done
+	EXT=${DOFILE#default}
+	EXT=${EXT%.do}
+	BASE=${1%$EXT}
+}
+
+
+_find_dofile()
+{
+	PREFIX=
+	while :; do
+		_find_dofile_pwd "$1"
+		[ -e "$DOFILE" ] && break
+		[ "$PWD" = "/" ] && break
+		TARGET=${PWD##*/}/$TARGET
+		PREFIX=${PWD##*/}/$PREFIX
+		cd ..
+	done
+	BASE=$PREFIX$BASE
+}
+
+
+_run_dofile()
+{
+	export DO_DEPTH="$DO_DEPTH  "
+	export REDO_TARGET=$PWD/$TARGET
+	set -e
+	read line1 <"$PWD/$DOFILE"
+	cmd=${line1#"#!/"}
+	if [ "$cmd" != "$line1" ]; then
+		/$cmd "$PWD/$DOFILE" "$@" >"$TARGET.tmp2"
+	else
+		. "$PWD/$DOFILE" >"$TARGET.tmp2"
+	fi
+}
+
+
+_do()
+{
+	DIR=$1
+	TARGET=$2
+	if [ ! -e "$TARGET" ] || [ -e "$TARGET/." -a ! -e "$TARGET.did" ]; then
+		printf '%sdo  %s%s%s%s\n' \
+			"$GREEN" "$DO_DEPTH" "$BOLD" "$DIR$TARGET" "$PLAIN" >&2
+		echo "$PWD/$TARGET" >>"$DO_BUILT"
+		DOFILE=$TARGET.do
+		BASE=$TARGET
+		EXT=
+		[ -e "$TARGET.do" ] || _find_dofile "$TARGET"
+		if [ ! -e "$DOFILE" ]; then
+			echo "do: $TARGET: no .do file" >&2
+			return 1
+		fi
+		[ ! -e "$DO_BUILD" ] || : >>"$TARGET.did"
+		( _run_dofile "$BASE" "$EXT" "$TARGET.tmp" )
+		RV=$?
+		if [ $RV != 0 ]; then
+			printf "do: %s%s\n" "$DO_DEPTH" \
+				"$DIR$TARGET: got exit code $RV" >&2
+			rm -f "$TARGET.tmp" "$TARGET.tmp2"
+			return $RV
+		fi
+		mv "$TARGET.tmp" "$TARGET" 2>/dev/null ||
+		! test -s "$TARGET.tmp2" ||
+		mv "$TARGET.tmp2" "$TARGET" 2>/dev/null
+		rm -f "$TARGET.tmp2"
+	else
+		echo "do  $DO_DEPTH$TARGET exists." >&2
+	fi
+}
+
+
+redo()
+{
+	for i in "$@"; do
+		_dirsplit "$i"
+		( cd "$dir" && _do "$dir" "$base" ) || return 1
+	done
+}
+
+
+set -e
+redo "$@"
+
+if [ -n "$DO_TOP" ]; then
+	echo "Removing stamp files..." >&2
+	[ ! -e "$DO_BUILT" ] ||
+	while read f; do printf "%s.did\0" "$f"; done <"$DO_BUILT" |
+	xargs -0 rm -f 2>/dev/null
+fi