diff --git a/utils/renamer.pl b/utils/renamer.pl
new file mode 100755
index 000000000..9845e36c4
--- /dev/null
+++ b/utils/renamer.pl
@@ -0,0 +1,58 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+
+my ($fromdir, $renamefile, $todir) = @ARGV;
+
+sub usage {
+  die "usage: $0 [fromdir] [renamefile] [todir]\n
+  takes files from [fromdir], renames according to the json-map in
+  [renamefile] and writes the files to [todir].
+  old filenames are used as keys; new filenames as value\n";
+}
+
+usage() unless $fromdir and $renamefile and $todir;
+usage() unless -d $fromdir;
+usage() unless -f $renamefile;
+
+mkdir $todir;
+
+my %did = ();
+
+my @errNex = ();
+
+my $fh = undef;
+open($fh, '<', $renamefile) or die "Cannot read '$renamefile', because: $!";
+my $cont = join '', <$fh>;
+close $fh;
+if($cont!~m#^\s*\{(.*)\}\s*$#s) { die "'$renamefile' not in an expected format; it should be an json-object" }
+my $core = $1;
+
+while($core=~s#^\s*,?\s*"([^"/]+)"\s*:\s*"([^"/]+)"##) {
+  my ($from, $to) = ($1, $2);
+  my $pfrom = "$fromdir/$from";
+  my $pto = "$todir/$to";
+  if(-e $pfrom) {
+    print "Renaming '$pfrom' to '$pto'\n";
+    system("cp", $pfrom, $pto);
+    $did{$from} = 1;
+  } else {
+    push @errNex, $from
+  }
+}
+
+for(@errNex) {
+  warn "Could not rename non-existent file: $_\n";
+}
+
+die "Syntax error in [renamefile], could not process everything!" if $core!~m#^[\s*,]*$#;
+
+my $dh = undef;
+opendir($dh, $fromdir) or die "Could not read dir '$fromdir', because: $!";
+while(my $filename = readdir($dh)) {
+  next if $filename=~m#^\.\.?$#;
+  warn "Did not touch not mentioned file '$filename'\n" unless $did{$filename};
+}
+
+