diff --git a/lib/WebGUI/Upgrade.pm b/lib/WebGUI/Upgrade.pm
new file mode 100644
index 000000000..b60b62854
--- /dev/null
+++ b/lib/WebGUI/Upgrade.pm
@@ -0,0 +1,157 @@
+package WebGUI::Upgrade;
+
+use strict;
+use warnings;
+use WebGUI::Paths;
+use WebGUI;
+
+sub upgradeSite {
+    my $class = shift;
+    my ($configFile) = @_;
+    my $fromVersion = '7.8.1';
+    my $steps = $class->calcUpgradePath($fromVersion);
+    for my $step ( @$steps ) {
+        $class->runUpgradeStep($configFile, $step);
+    }
+}
+
+sub upgradeSites {
+    my $class = shift;
+    my @configs = WebGUI::Paths->siteConfigs;
+    for my $configFile (@configs) {
+        $class->upgradeSite($configFile);
+    }
+}
+
+sub calcUpgradePath {
+    my $class = shift;
+    my $fromVersion = $class->decimalize_version(shift);
+    my $toVersion = $class->decimalize_version('7.9.3'); #$WebGUI::VERSION);
+
+    my %from;
+    opendir my $dh, WebGUI::Paths->upgrades;
+    while ( my $dir = readdir $dh ) {
+        next
+            if $dir =~ /^\./;
+        next
+            unless -d File::Spec->catdir(WebGUI::Paths->upgrades, $dir);
+        if ($dir =~ /^(\d+\.\d+\.\d+)-(\d+\.\d+\.\d+)$/) {
+            $from{ $class->decimalize_version($1) }{ $class->decimalize_version($2) } = "$1-$2";
+        }
+    }
+    closedir $dh;
+
+    my $findSteps;
+    $findSteps = sub {
+        my ($found, $steps) = @_;
+        if ($found eq $toVersion) {
+            return $steps;
+        }
+        my $stepsAvail = $from{$found};
+        for my $nextStep ( sort { $a <=> $b } keys %{ $stepsAvail } ) {
+            my $doneSteps = $findSteps->($nextStep, [@$steps, $stepsAvail->{$nextStep}]);
+            return $doneSteps
+                if $doneSteps;
+        }
+        return;
+    };
+    my $steps = $findSteps->($fromVersion, []);
+    return $steps;
+}
+
+sub runUpgradeStep {
+    my $class = shift;
+    my ($configFile, $step) = @_;
+    print "Running upgrade $step\n";
+    my $upgradesDir = File::Spec->catdir(WebGUI::Paths->upgrades, $step);
+    opendir my($dh), $upgradesDir;
+    while ( my $upgradeFile = readdir $dh ) {
+        next
+            if $upgradeFile =~ /^\./;
+        my $filename = File::Spec->catfile($upgradesDir, $upgradeFile);
+        next
+            unless -f $filename;
+        my ($extension) = $filename =~ /\.([^.]+)$/;
+        next
+            unless $extension;
+        my $sub = __PACKAGE__->can('upgrade_file_' . $extension);
+        if ($sub) {
+            $class->$sub($configFile, $filename);
+        }
+        else {
+            warn "Don't know how to use $extension upgrade file\n";
+        }
+    }
+    closedir $dh;
+}
+
+sub decimalize_version {
+    my $class = shift;
+    my $version = shift;
+    my @parts = split /\./, $version;
+    my $decVersion = 0;
+    for my $i (0..$#parts) {
+        $decVersion += $parts[$i] / (1000**$i);
+    }
+    return $decVersion;
+}
+
+sub upgrade_file_pl {
+    my $class = shift;
+    my ($configFile, $file) = @_;
+    open my $fh, '<', $file;
+    my $contents = do { local $/; <$fh> };
+    close $fh;
+    my $code = sprintf <<'END_CODE', $file, $contents;
+package WebGUI::Upgrade::Script;
+use strict;
+use warnings;
+# line 1 "%s"
+%s
+END_CODE
+    my $pid = fork;
+    if (!$pid) {
+        $WebGUI::Upgrade::Script::configFile = $configFile;
+        $WebGUI::Upgrade::Script::quiet = 0;
+        eval $code;
+        die $@ if $@;
+        exit;
+    }
+    waitpid $pid, 0;
+}
+
+sub upgrade_file_sql {
+    my $class = shift;
+    my ($configFile, $file) = @_;
+    warn "running sql script: $file\n";
+}
+
+package WebGUI::Upgrade::Script;
+
+our $configFile;
+our $config;
+our $session;
+our $quiet;
+
+sub report {
+    print @_ unless $quiet;
+}
+
+sub done {
+    print "Done.\n" unless $quiet;
+}
+
+sub session () {
+    require WebGUI::Session;
+    $session ||= WebGUI::Session->open(config());
+    return $session;
+}
+
+sub config () {
+    require WebGUI::Config;
+    $config ||= WebGUI::Config->new($configFile, 1);
+    return $config;
+}
+
+1;
+
diff --git a/var/upgrades/7.8.1-7.8.2/.exists b/var/upgrades/7.8.1-7.8.2/.exists
new file mode 100644
index 000000000..e69de29bb
diff --git a/var/upgrades/7.8.1-7.9.1/.exists b/var/upgrades/7.8.1-7.9.1/.exists
new file mode 100644
index 000000000..e69de29bb
diff --git a/var/upgrades/7.8.2-7.8.3/.exists b/var/upgrades/7.8.2-7.8.3/.exists
new file mode 100644
index 000000000..e69de29bb
diff --git a/var/upgrades/7.8.3-7.9.3/.exists b/var/upgrades/7.8.3-7.9.3/.exists
new file mode 100644
index 000000000..e69de29bb
diff --git a/var/upgrades/7.8.3-7.9.3/script1.pl b/var/upgrades/7.8.3-7.9.3/script1.pl
new file mode 100644
index 000000000..68f3ed78a
--- /dev/null
+++ b/var/upgrades/7.8.3-7.9.3/script1.pl
@@ -0,0 +1,3 @@
+report "stuff\n";
+
+done;
diff --git a/var/upgrades/7.8.3-7.9.3/script2.pl b/var/upgrades/7.8.3-7.9.3/script2.pl
new file mode 100644
index 000000000..4199d8f67
--- /dev/null
+++ b/var/upgrades/7.8.3-7.9.3/script2.pl
@@ -0,0 +1,6 @@
+report "Doing something more interesting\n";
+
+report session->db->quickScalar('SELECT count(*) from asset');
+
+done;
+
diff --git a/var/upgrades/7.9.1-7.9.2/.exists b/var/upgrades/7.9.1-7.9.2/.exists
new file mode 100644
index 000000000..e69de29bb
diff --git a/var/upgrades/7.9.2-7.9.3/.exists b/var/upgrades/7.9.2-7.9.3/.exists
new file mode 100644
index 000000000..e69de29bb