diff --git a/tools/tinderbox/multi-tinderbox.pl b/tools/tinderbox/multi-tinderbox.pl
new file mode 100755
index 00000000000..9a118c9ec60
--- /dev/null
+++ b/tools/tinderbox/multi-tinderbox.pl
@@ -0,0 +1,75 @@
+#!/usr/bin/perl
+# vim:sw=4:et:ts=4:ai:
+
+use strict;
+
+sub PrintUsage() {
+    die <<END_USAGE
+    usage: $0 [options]
+Options:
+  --example-config       Instead of running, print an example
+                           'multi-config.pl' to help get started.
+END_USAGE
+}
+
+sub PrintExample() {
+    print <<END_EXAMPLE
+# multi-config.pl
+\$BuildSleep = 10;                       # minutes
+\$Tinderboxes = [ { tree => "SeaMonkey", args => "--depend --mozconfig mozconfig" }, { tree => "SeaMonkey-Branch", args => "--depend --mozconfig mozconfig" } ];
+END_EXAMPLE
+    ;
+    exit;
+}
+
+sub HandleArgs() {
+    return if ($#ARGV == -1);
+    PrintUsage() if ($#ARGV != 0 || $ARGV[0] ne "--example-config");
+    PrintExample();
+}
+
+sub LoadConfig() {
+    if (-r 'multi-config.pl') {
+        no strict 'vars';
+
+        open CONFIG, 'multi-config.pl' or
+            print "can't open multi-config.pl, $?\n";
+
+        while (<CONFIG>) {
+            package Settings;
+            eval;
+        }
+
+        close CONFIG;
+    } else {
+        warn "Error: Need tinderbox config file, multi-config.pl\n";
+        exit;
+    }
+}
+
+
+sub Run() {
+    my $start_time = 0;
+    while (1) {
+        # $BuildSleep is the minimum amount of time a build is allowed to take.
+        # It prevents sending too many messages to the tinderbox server when
+        # something is broken.
+        my $sleep_time = ($Settings::BuildSleep * 60) - (time() - $start_time);
+        if ($sleep_time > 0) {
+            print "\n\nSleeping $sleep_time seconds ...\n";
+            sleep $sleep_time;
+        }
+        $start_time = time();
+
+        foreach my $treeentry (@{$Settings::Tinderboxes}) {
+            chdir($treeentry->{tree}) or
+                die "Tree $treeentry->{tree} does not exist";
+            system("./build-seamonkey.pl --once $treeentry->{args}");
+            chdir("..");
+        }
+    }
+}
+
+HandleArgs();
+LoadConfig();
+Run();