diff --git a/lib/Slic3r.pm b/lib/Slic3r.pm
index 12a5aa428..984ebc92f 100644
--- a/lib/Slic3r.pm
+++ b/lib/Slic3r.pm
@@ -56,7 +56,6 @@ use Slic3r::GCode::PlaceholderParser;
 use Slic3r::GCode::Reader;
 use Slic3r::GCode::SpiralVase;
 use Slic3r::GCode::VibrationLimit;
-use Slic3r::GCode::Writer;
 use Slic3r::Geometry qw(PI);
 use Slic3r::Geometry::Clipper;
 use Slic3r::Layer;
@@ -177,6 +176,7 @@ sub thread_cleanup {
     *Slic3r::ExtrusionPath::Collection::DESTROY = sub {};
     *Slic3r::Flow::DESTROY                  = sub {};
     *Slic3r::GCode::PlaceholderParser::DESTROY = sub {};
+    *Slic3r::GCode::Writer::DESTROY         = sub {};
     *Slic3r::Geometry::BoundingBox::DESTROY = sub {};
     *Slic3r::Geometry::BoundingBoxf::DESTROY = sub {};
     *Slic3r::Geometry::BoundingBoxf3::DESTROY = sub {};
diff --git a/lib/Slic3r/GCode.pm b/lib/Slic3r/GCode.pm
index 03ef4ea94..7f36b5f50 100644
--- a/lib/Slic3r/GCode.pm
+++ b/lib/Slic3r/GCode.pm
@@ -271,7 +271,7 @@ sub _extrude_path {
     
     # calculate extrusion length per distance unit
     my $e_per_mm = $self->writer->extruder->e_per_mm3 * $path->mm3_per_mm;
-    $e_per_mm = 0 if !$self->writer->_extrusion_axis;
+    $e_per_mm = 0 if !$self->writer->extrusion_axis;
     
     # set speed
     my $F;
@@ -307,7 +307,7 @@ sub _extrude_path {
         $gcode .= $path->gcode($self->writer->extruder, $e_per_mm, $F,
             $self->origin->x - $extruder_offset->x,
             $self->origin->y - $extruder_offset->y,  #-
-            $self->writer->_extrusion_axis,
+            $self->writer->extrusion_axis,
             $self->config->gcode_comments ? " ; $description" : "");
 
         if ($self->enable_wipe) {
@@ -375,7 +375,7 @@ sub travel_to {
         # If avoid_crossing_perimeters is disabled or the straight_once flag is set,
         # perform a straight move with a retraction.
         $gcode .= $self->retract;
-        $gcode .= $self->writer->travel_to_xy($self->point_to_gcode($point), $comment);
+        $gcode .= $self->writer->travel_to_xy($self->point_to_gcode($point), $comment || '');
     }
     
     # Re-allow avoid_crossing_perimeters for the next travel moves
@@ -425,7 +425,7 @@ sub retract {
     if ($self->config->get_at('wipe', $self->writer->extruder->id) && $self->_wipe_path) {
         # Reduce feedrate a bit; travel speed is often too high to move on existing material.
         # Too fast = ripping of existing material; too slow = short wipe path, thus more blob.
-        my $wipe_speed = $self->writer->config->travel_speed * 0.8;
+        my $wipe_speed = $self->writer->config->get('travel_speed') * 0.8;
         
         # get the retraction length
         my $length = $toolchange
@@ -484,7 +484,7 @@ sub unretract {
     
     my $gcode = "";
     $gcode .= $self->writer->unlift;
-    $gcode .= $self->writer->unretract('compensate retraction');
+    $gcode .= $self->writer->unretract;
     return $gcode;
 }
 
diff --git a/lib/Slic3r/GCode/Writer.pm b/lib/Slic3r/GCode/Writer.pm
deleted file mode 100644
index 931cdd3c1..000000000
--- a/lib/Slic3r/GCode/Writer.pm
+++ /dev/null
@@ -1,426 +0,0 @@
-package Slic3r::GCode::Writer;
-use Moo;
-
-use List::Util qw(min max first);
-use Slic3r::Geometry qw(X Y epsilon);
-
-has 'config'                => (is => 'ro', default => sub { Slic3r::Config::GCode->new });
-has 'multiple_extruders'    => (is => 'rw', default => sub { 0 });
-has '_extrusion_axis'       => (is => 'rw', default => sub { 'E' });
-has '_extruders'            => (is => 'ro', default => sub {{}});
-has '_extruder'             => (is => 'rw', reader => 'extruder');
-has '_last_acceleration'    => (is => 'rw', default => sub { 0 });
-has '_last_fan_speed'       => (is => 'rw', default => sub { 0 });
-has '_lifted'               => (is => 'rw', default => sub { 0 });
-has '_pos'                  => (is => 'rw', default => sub { Slic3r::Pointf3->new });
-
-sub apply_print_config {
-    my ($self, $print_config) = @_;
-    
-    $self->config->apply_print_config($print_config);
-    
-    if ($self->config->gcode_flavor eq 'mach3') {
-        $self->_extrusion_axis('A');
-    } elsif ($self->config->gcode_flavor eq 'no-extrusion') {
-        $self->_extrusion_axis('');
-    } else {
-        $self->_extrusion_axis($self->config->extrusion_axis);
-    }
-}
-
-sub set_extruders {
-    my ($self, $extruder_ids) = @_;
-    
-    foreach my $i (@$extruder_ids) {
-        $self->_extruders->{$i} = my $e = Slic3r::Extruder->new($i, $self->config);
-    }
-    
-    # we enable support for multiple extruder if any extruder greater than 0 is used
-    # (even if prints only uses that one) since we need to output Tx commands
-    # first extruder has index 0
-    $self->multiple_extruders(max(@$extruder_ids) > 0);
-}
-
-sub preamble {
-    my ($self) = @_;
-    
-    my $gcode = "";
-    
-    if ($self->config->gcode_flavor ne 'makerware') {
-        $gcode .= "G21 ; set units to millimeters\n";
-        $gcode .= "G90 ; use absolute coordinates\n";
-    }
-    if ($self->config->gcode_flavor =~ /^(?:reprap|teacup)$/) {
-        if ($self->config->use_relative_e_distances) {
-            $gcode .= "M83 ; use relative distances for extrusion\n";
-        } else {
-            $gcode .= "M82 ; use absolute distances for extrusion\n";
-        }
-        $gcode .= $self->reset_e(1);
-    }
-    return $gcode;
-}
-
-sub set_temperature {
-    my ($self, $temperature, $wait, $tool) = @_;
-    
-    return "" if $wait && $self->config->gcode_flavor =~ /^(?:makerware|sailfish)$/;
-    
-    my ($code, $comment) = ($wait && $self->config->gcode_flavor ne 'teacup')
-        ? ('M109', 'wait for temperature to be reached')
-        : ('M104', 'set temperature');
-    my $gcode = sprintf "$code %s%d %s; $comment\n",
-        ($self->config->gcode_flavor eq 'mach3' ? 'P' : 'S'), $temperature,
-        (defined $tool && ($self->multiple_extruders || $self->config->gcode_flavor =~ /^(?:makerware|sailfish)$/)) ? "T$tool " : "";
-    
-    $gcode .= "M116 ; wait for temperature to be reached\n"
-        if $self->config->gcode_flavor eq 'teacup' && $wait;
-    
-    return $gcode;
-}
-
-sub set_bed_temperature {
-    my ($self, $temperature, $wait) = @_;
-    
-    my ($code, $comment) = ($wait && $self->config->gcode_flavor ne 'teacup')
-        ? (($self->config->gcode_flavor =~ /^(?:makerware|sailfish)$/ ? 'M109' : 'M190'), 'wait for bed temperature to be reached')
-        : ('M140', 'set bed temperature');
-    my $gcode = sprintf "$code %s%d ; $comment\n",
-        ($self->config->gcode_flavor eq 'mach3' ? 'P' : 'S'), $temperature;
-    
-    $gcode .= "M116 ; wait for bed temperature to be reached\n"
-        if $self->config->gcode_flavor eq 'teacup' && $wait;
-    
-    return $gcode;
-}
-
-sub set_fan {
-    my ($self, $speed, $dont_save) = @_;
-    
-    if ($self->_last_fan_speed != $speed || $dont_save) {
-        $self->_last_fan_speed($speed) if !$dont_save;
-        if ($speed == 0) {
-            my $code = $self->config->gcode_flavor eq 'teacup'
-                ? 'M106 S0'
-                : $self->config->gcode_flavor =~ /^(?:makerware|sailfish)$/
-                    ? 'M127'
-                    : 'M107';
-            return sprintf "$code%s\n", ($self->config->gcode_comments ? ' ; disable fan' : '');
-        } else {
-            if ($self->config->gcode_flavor =~ /^(?:makerware|sailfish)$/) {
-                return sprintf "M126%s\n", ($self->config->gcode_comments ? ' ; enable fan' : '');
-            } else {
-                return sprintf "M106 %s%d%s\n", ($self->config->gcode_flavor eq 'mach3' ? 'P' : 'S'),
-                    (255 * $speed / 100), ($self->config->gcode_comments ? ' ; enable fan' : '');
-            }
-        }
-    }
-    return "";
-}
-
-sub set_acceleration {
-    my ($self, $acceleration) = @_;
-    
-    return "" if !$acceleration || $acceleration == $self->_last_acceleration;
-    
-    $self->_last_acceleration($acceleration);
-    return sprintf "M204 S%s%s\n",
-        $acceleration, ($self->config->gcode_comments ? ' ; adjust acceleration' : '');
-}
-
-sub update_progress {
-    my ($self, $num, $tot, $allow_100) = @_;
-    
-    return "" if $self->config->gcode_flavor !~ /^(?:makerware|sailfish)$/;
-    
-    my $percent = int($num/$tot*100);
-    $percent = min($percent, 99) if !$allow_100;
-    return sprintf "M73 P%s%s\n",
-        $percent,
-        $self->_comment('update progress');
-}
-
-sub need_toolchange {
-    my ($self, $extruder_id) = @_;
-    
-    # return false if this extruder was already selected
-    return (!defined $self->_extruder) || ($self->_extruder->id != $extruder_id);
-}
-
-sub set_extruder {
-    my ($self, $extruder_id) = @_;
-    
-    return "" if !$self->need_toolchange;
-    return $self->toolchange($extruder_id);
-}
-
-sub toolchange {
-    my ($self, $extruder_id) = @_;
-    
-    # set the new extruder
-    $self->_extruder($self->_extruders->{$extruder_id});
-    
-    # return the toolchange command
-    # if we are running a single-extruder setup, just set the extruder and return nothing
-    my $gcode = "";
-    if ($self->multiple_extruders) {
-        $gcode .= sprintf "%s%d%s\n",
-            ($self->config->gcode_flavor eq 'makerware'
-                ? 'M135 T'
-                : $self->config->gcode_flavor eq 'sailfish'
-                    ? 'M108 T'
-                    : 'T'),
-            $extruder_id,
-            ($self->config->gcode_comments ? ' ; change extruder' : '');
-        
-        $gcode .= $self->reset_e(1);
-    }
-    return $gcode;
-}
-
-sub reset_e {
-    my ($self, $force) = @_;
-    
-    return "" if $self->config->gcode_flavor =~ /^(?:mach3|makerware|sailfish)$/;
-    
-    if (defined $self->_extruder) {
-        return "" if $self->_extruder->E == 0 && !$force;
-        $self->_extruder->set_E(0) if $self->_extruder;
-    }
-    
-    if ($self->_extrusion_axis ne '' && !$self->config->use_relative_e_distances) {
-        return sprintf "G92 %s0%s\n", $self->config->extrusion_axis, ($self->config->gcode_comments ? ' ; reset extrusion distance' : '');
-    } else {
-        return "";
-    }
-}
-
-sub _comment {
-    my ($self, $comment) = @_;
-    
-    return "" if (!defined $comment) || ($comment eq '') || !$self->config->gcode_comments;
-    return " ; $comment";
-}
-
-sub set_speed {
-    my ($self, $F, $comment) = @_;
-    
-    return sprintf "G1 F%.3f%s\n",
-        $F,
-        $self->_comment($comment);
-}
-
-sub travel_to_xy {
-    my ($self, $pointf, $comment) = @_;
-    
-    $self->_pos->set_x($pointf->x);
-    $self->_pos->set_y($pointf->y);     # ))
-    return sprintf "G1 X%.3f Y%.3f F%.3f%s\n",
-        @$pointf,
-        $self->config->travel_speed*60,
-        $self->_comment($comment);
-}
-
-sub travel_to_xyz {
-    my ($self, $pointf3, $comment) = @_;
-    
-    # If target Z is lower than current Z but higher than nominal Z we
-    # don't perform the Z move but we only move in the XY plane and
-    # adjust the nominal Z by reducing the lift amount that will be 
-    # used for unlift.
-    if (!$self->will_move_z($pointf3->z)) {
-        my $nominal_z = $self->_pos->z - $self->_lifted;
-        $self->_lifted($self->_lifted - ($pointf3->z - $nominal_z));
-        return $self->travel_to_xy(Slic3r::Pointf->new(@$pointf3[X,Y]));
-    }
-    
-    # In all the other cases, we perform an actual XYZ move and cancel
-    # the lift.
-    $self->_lifted(0);
-    return $self->_travel_to_xyz($pointf3, $comment);
-}
-
-sub _travel_to_xyz {
-    my ($self, $pointf3, $comment) = @_;
-    
-    $self->_pos($pointf3);
-    return sprintf "G1 X%.3f Y%.3f Z%.3f F%.3f%s\n",
-        @$pointf3,
-        $self->config->travel_speed*60,
-        $self->_comment($comment);
-}
-
-sub travel_to_z {
-    my ($self, $z, $comment) = @_;
-    
-    # If target Z is lower than current Z but higher than nominal Z
-    # we don't perform the move but we only adjust the nominal Z by
-    # reducing the lift amount that will be used for unlift.
-    if (!$self->will_move_z($z)) {
-        my $nominal_z = $self->_pos->z - $self->_lifted;
-        $self->_lifted($self->_lifted - ($z - $nominal_z));
-        return "";
-    }
-    
-    # In all the other cases, we perform an actual Z move and cancel
-    # the lift.
-    $self->_lifted(0);
-    return $self->_travel_to_z($z, $comment);
-}
-
-sub _travel_to_z {
-    my ($self, $z, $comment) = @_;
-    
-    $self->_pos->set_z($z);
-    return sprintf "G1 Z%.3f F%.3f%s\n",
-        $z,
-        $self->config->travel_speed*60,
-        $self->_comment($comment);
-}
-
-sub will_move_z {
-    my ($self, $z) = @_;
-    
-    # If target Z is lower than current Z but higher than nominal Z
-    # we don't perform an actual Z move.
-    if ($self->_lifted > 0) {
-        my $nominal_z = $self->_pos->z - $self->_lifted;
-        if ($z >= $nominal_z && $z <= $self->_pos->z) {
-            return 0;
-        }
-    }
-    return 1;
-}
-
-sub extrude_to_xy {
-    my ($self, $pointf, $dE, $comment) = @_;
-    
-    $self->_pos->set_x($pointf->x);
-    $self->_pos->set_y($pointf->y);     # ))
-    $self->_extruder->extrude($dE);
-    return sprintf "G1 X%.3f Y%.3f %s%.5f%s\n",
-        @$pointf,
-        $self->_extrusion_axis,
-        $self->_extruder->E,
-        $self->_comment($comment);
-}
-
-sub extrude_to_xyz {
-    my ($self, $pointf3, $dE, $comment) = @_;
-    
-    $self->_pos($pointf3);
-    $self->_lifted(0);
-    $self->_extruder->extrude($dE);
-    return sprintf "G1 X%.3f Y%.3f Z%.3f %s%.5f%s\n",
-        @$pointf3,
-        $self->_extrusion_axis,
-        $self->_extruder->E,
-        $self->_comment($comment);
-}
-
-sub retract {
-    my ($self) = @_;
-    
-    return $self->_retract(
-        $self->_extruder->retract_length,
-        $self->_extruder->retract_restart_extra,
-        'retract',
-    );
-}
-
-sub retract_for_toolchange {
-    my ($self) = @_;
-    
-    return $self->_retract(
-        $self->_extruder->retract_length_toolchange,
-        $self->_extruder->retract_restart_extra_toolchange,
-        'retract for toolchange',
-    );
-}
-
-sub _retract {
-    my ($self, $length, $restart_extra, $comment) = @_;
-    
-    my $gcode = "";
-    my $dE = $self->_extruder->retract($length, $restart_extra);
-    if ($dE != 0) {
-        if ($self->config->use_firmware_retraction) {
-            $gcode .= "G10 ; retract\n";
-        } else {
-            $gcode = sprintf "G1 %s%.5f F%.3f%s\n",
-                $self->_extrusion_axis,
-                $self->_extruder->E,
-                $self->_extruder->retract_speed_mm_min,
-                $self->_comment($comment);
-        }
-    }
-    
-    $gcode .= "M103 ; extruder off\n"
-        if $self->config->gcode_flavor eq 'makerware';
-    
-    return $gcode;
-}
-
-sub unretract {
-    my ($self, $comment) = @_;
-    
-    my $gcode = "";
-    
-    $gcode .= "M101 ; extruder on\n"
-        if $self->config->gcode_flavor eq 'makerware';
-    
-    my $dE = $self->_extruder->unretract;
-    if ($dE != 0) {
-        if ($self->config->use_firmware_retraction) {
-            $gcode .= "G11 ; unretract\n";
-            $gcode .= $self->reset_e;
-            return $gcode;
-        } else {
-            # use G1 instead of G0 because G0 will blend the restart with the previous travel move
-            $gcode .= sprintf "G1 %s%.5f F%.3f%s\n",
-                $self->_extrusion_axis,
-                $self->_extruder->E,
-                $self->_extruder->retract_speed_mm_min,
-                $self->_comment($comment);
-        }
-    }
-    
-    return $gcode;
-}
-
-# If this method is called more than once before calling unlift(),
-# it will not perform subsequent lifts, even if Z was raised manually
-# (i.e. with travel_to_z()) and thus _lifted was reduced.
-sub lift {
-    my ($self) = @_;
-    
-    if ($self->_lifted == 0 && $self->config->retract_lift->[0] > 0) {
-        my $to_lift = $self->config->retract_lift->[0];
-        $self->_lifted($to_lift);
-        return $self->_travel_to_z($self->_pos->z + $to_lift, 'lift Z');
-    }
-    return "";
-}
-
-sub unlift {
-    my ($self) = @_;
-    
-    my $gcode = "";
-    if ($self->_lifted > 0) {
-        $gcode .= $self->_travel_to_z($self->_pos->z - $self->_lifted, 'restore layer Z');
-        $self->_lifted(0);
-    }
-    return $gcode;
-}
-
-sub hasmultiple_extruders {
-    my ($self) = @_;
-    return $self->multiple_extruders;
-}
-
-sub extruders {
-    my ($self) = @_;
-    return [ sort { $a->id <=> $b->id } values %{$self->_extruders} ];
-}
-
-1;
diff --git a/lib/Slic3r/Print.pm b/lib/Slic3r/Print.pm
index 83290cb2b..b50cfbaf6 100644
--- a/lib/Slic3r/Print.pm
+++ b/lib/Slic3r/Print.pm
@@ -633,7 +633,7 @@ sub write_gcode {
                     if ($layer->id == 0 && $finished_objects > 0) {
                         printf $fh $gcodegen->writer->set_bed_temperature($self->config->first_layer_bed_temperature),
                             if $self->config->first_layer_bed_temperature;
-                        $print_first_layer_temperature->();
+                        $print_first_layer_temperature->(0);
                     }
                     print $fh $buffer->append(
                         $layer_gcode->process_layer($layer, [$copy]),
diff --git a/xs/lib/Slic3r/XS.pm b/xs/lib/Slic3r/XS.pm
index 4e112eda4..dbb4df69c 100644
--- a/xs/lib/Slic3r/XS.pm
+++ b/xs/lib/Slic3r/XS.pm
@@ -190,6 +190,7 @@ package main;
 for my $class (qw(
         Slic3r::Config
         Slic3r::Config::Full
+        Slic3r::Config::GCode
         Slic3r::Config::Print
         Slic3r::Config::PrintObject
         Slic3r::Config::PrintRegion
diff --git a/xs/src/libslic3r/GCodeWriter.cpp b/xs/src/libslic3r/GCodeWriter.cpp
new file mode 100644
index 000000000..0133c2265
--- /dev/null
+++ b/xs/src/libslic3r/GCodeWriter.cpp
@@ -0,0 +1,499 @@
+#include "GCodeWriter.hpp"
+#include <algorithm>
+#include <iomanip>
+#include <iostream>
+#include <map>
+
+#define FLAVOR_IS(val) this->config.gcode_flavor == val
+#define FLAVOR_IS_NOT(val) this->config.gcode_flavor != val
+#define COMMENT(comment) if (this->config.gcode_comments && !comment.empty()) gcode << " ; " << comment;
+#define PRECISION(val, precision) std::fixed << std::setprecision(precision) << val
+#define XYZF_NUM(val) PRECISION(val, 3)
+#define E_NUM(val) PRECISION(val, 5)
+
+namespace Slic3r {
+
+Extruder*
+GCodeWriter::extruder()
+{
+    return this->_extruder;
+}
+
+std::string
+GCodeWriter::extrusion_axis() const
+{
+    return this->_extrusion_axis;
+}
+
+void
+GCodeWriter::apply_print_config(const PrintConfig &print_config)
+{
+    this->config.apply(print_config, true);
+    
+    if (FLAVOR_IS(gcfMach3)) {
+        this->_extrusion_axis = "A";
+    } else if (FLAVOR_IS(gcfNoExtrusion)) {
+        this->_extrusion_axis = "";
+    } else {
+        this->_extrusion_axis = this->config.extrusion_axis;
+    }
+}
+
+void
+GCodeWriter::set_extruders(const std::vector<unsigned int> &extruder_ids)
+{
+    for (std::vector<unsigned int>::const_iterator i = extruder_ids.begin(); i != extruder_ids.end(); ++i) {
+        this->extruders.insert( std::pair<unsigned int,Extruder>(*i, Extruder(*i, &this->config)) );
+    }
+    
+    /*  we enable support for multiple extruder if any extruder greater than 0 is used
+        (even if prints only uses that one) since we need to output Tx commands
+        first extruder has index 0 */
+    this->multiple_extruders = (*std::max_element(extruder_ids.begin(), extruder_ids.end())) > 0;
+}
+
+std::string
+GCodeWriter::preamble()
+{
+    std::string gcode;
+    
+    if (FLAVOR_IS_NOT(gcfMakerWare)) {
+        gcode += "G21 ; set units to millimeters\n";
+        gcode += "G90 ; use absolute coordinates\n";
+    }
+    if (FLAVOR_IS(gcfRepRap) || FLAVOR_IS(gcfTeacup)) {
+        if (this->config.use_relative_e_distances) {
+            gcode += "M83 ; use relative distances for extrusion\n";
+        } else {
+            gcode += "M82 ; use absolute distances for extrusion\n";
+        }
+        gcode += this->reset_e(true);
+    }
+    
+    return gcode;
+}
+
+std::string
+GCodeWriter::set_temperature(unsigned int temperature, bool wait, int tool)
+{
+    if (wait && (FLAVOR_IS(gcfMakerWare) || FLAVOR_IS(gcfSailfish)))
+        return "";
+    
+    std::string code, comment;
+    if (wait && FLAVOR_IS_NOT(gcfTeacup)) {
+        code = "M109";
+        comment = "wait for temperature to be reached";
+    } else {
+        code = "M104";
+        comment = "set temperature";
+    }
+    
+    std::ostringstream gcode;
+    gcode << code << " ";
+    if (FLAVOR_IS(gcfMach3)) {
+        gcode << "P";
+    } else {
+        gcode << "S";
+    }
+    gcode << temperature;
+    if (tool != -1 && (this->multiple_extruders || FLAVOR_IS(gcfMakerWare) || FLAVOR_IS(gcfSailfish))) {
+        gcode << " T" << tool;
+    }
+    gcode << " ; " << comment << "\n";
+    
+    if (FLAVOR_IS(gcfTeacup) && wait)
+        gcode << "M116 ; wait for temperature to be reached\n";
+    
+    return gcode.str();
+}
+
+std::string
+GCodeWriter::set_bed_temperature(unsigned int temperature, bool wait)
+{
+    std::string code, comment;
+    if (wait && FLAVOR_IS_NOT(gcfTeacup)) {
+        if (FLAVOR_IS(gcfMakerWare) || FLAVOR_IS(gcfSailfish)) {
+            code = "M109";
+        } else {
+            code = "M190";
+        }
+        comment = "set bed temperature";
+    } else {
+        code = "M140";
+        comment = "wait for bed temperature to be reached";
+    }
+    
+    std::ostringstream gcode;
+    gcode << code << " ";
+    if (FLAVOR_IS(gcfMach3)) {
+        gcode << "P";
+    } else {
+        gcode << "S";
+    }
+    gcode << temperature << " ; " << comment << "\n";
+    
+    if (FLAVOR_IS(gcfTeacup) && wait)
+        gcode << "M116 ; wait for bed temperature to be reached\n";
+    
+    return gcode.str();
+}
+
+std::string
+GCodeWriter::set_fan(unsigned int speed, bool dont_save)
+{
+    std::ostringstream gcode;
+    if (this->_last_fan_speed != speed || dont_save) {
+        if (!dont_save) this->_last_fan_speed = speed;
+        
+        if (speed == 0) {
+            if (FLAVOR_IS(gcfTeacup)) {
+                gcode << "M106 S0";
+            } else if (FLAVOR_IS(gcfMakerWare) || FLAVOR_IS(gcfSailfish)) {
+                gcode << "M127";
+            } else {
+                gcode << "M107";
+            }
+            if (this->config.gcode_comments) gcode << " ; disable fan";
+            gcode << "\n";
+        } else {
+            if (FLAVOR_IS(gcfMakerWare) || FLAVOR_IS(gcfSailfish)) {
+                gcode << "M126";
+            } else {
+                gcode << "M106 ";
+                if (FLAVOR_IS(gcfMach3)) {
+                    gcode << "P";
+                } else {
+                    gcode << "S";
+                }
+                gcode << (255.0 * speed / 100.0);
+            }
+            if (this->config.gcode_comments) gcode << " ; enable fan";
+            gcode << "\n";
+        }
+    }
+    return gcode.str();
+}
+
+std::string
+GCodeWriter::set_acceleration(unsigned int acceleration)
+{
+    if (acceleration == 0 || acceleration == this->_last_acceleration)
+        return "";
+    
+    this->_last_acceleration = acceleration;
+    
+    std::ostringstream gcode;
+    gcode << "M204 S" << acceleration;
+    if (this->config.gcode_comments) gcode << " ; adjust acceleration";
+    gcode << "\n";
+    
+    return gcode.str();
+}
+
+std::string
+GCodeWriter::reset_e(bool force)
+{
+    if (FLAVOR_IS(gcfMach3)
+        || FLAVOR_IS(gcfMakerWare)
+        || FLAVOR_IS(gcfSailfish))
+        return "";
+    
+    if (this->_extruder != NULL) {
+        if (this->_extruder->E == 0 && !force) return "";
+        this->_extruder->E = 0;
+    }
+    
+    if (!this->_extrusion_axis.empty() && !this->config.use_relative_e_distances) {
+        std::ostringstream gcode;
+        gcode << "G92 " << this->_extrusion_axis << "0";
+        if (this->config.gcode_comments) gcode << " ; reset extrusion distance";
+        gcode << "\n";
+        return gcode.str();
+    } else {
+        return "";
+    }
+}
+
+std::string
+GCodeWriter::update_progress(unsigned int num, unsigned int tot, bool allow_100)
+{
+    if (FLAVOR_IS_NOT(gcfMakerWare) && FLAVOR_IS_NOT(gcfSailfish))
+        return "";
+    
+    unsigned int percent = 100.0 * num / tot;
+    if (!allow_100) percent = std::min(percent, (unsigned int)99);
+    
+    std::ostringstream gcode;
+    gcode << "M73 P" << percent;
+    if (this->config.gcode_comments) gcode << " ; update progress";
+    gcode << "\n";
+    return gcode.str();
+}
+
+bool
+GCodeWriter::need_toolchange(unsigned int extruder_id) const
+{
+    // return false if this extruder was already selected
+    return (this->_extruder == NULL) || (this->_extruder->id != extruder_id);
+}
+
+std::string
+GCodeWriter::set_extruder(unsigned int extruder_id)
+{
+    if (!this->need_toolchange(extruder_id)) return "";
+    return this->toolchange(extruder_id);
+}
+
+std::string
+GCodeWriter::toolchange(unsigned int extruder_id)
+{
+    // set the new extruder
+    this->_extruder = &this->extruders.find(extruder_id)->second;
+    
+    // return the toolchange command
+    // if we are running a single-extruder setup, just set the extruder and return nothing
+    std::ostringstream gcode;
+    if (this->multiple_extruders) {
+        if (FLAVOR_IS(gcfMakerWare)) {
+            gcode << "M135 T";
+        } else if (FLAVOR_IS(gcfSailfish)) {
+            gcode << "M108 T";
+        } else {
+            gcode << "T";
+        }
+        gcode << extruder_id;
+        if (this->config.gcode_comments) gcode << " ; change extruder";
+        gcode << "\n";
+        
+        gcode << this->reset_e(true);
+    }
+    return gcode.str();
+}
+
+std::string
+GCodeWriter::set_speed(double F, const std::string &comment)
+{
+    std::ostringstream gcode;
+    gcode << "G1 F" << F;
+    COMMENT(comment);
+    gcode << "\n";
+    return gcode.str();
+}
+
+std::string
+GCodeWriter::travel_to_xy(const Pointf &point, const std::string &comment)
+{
+    this->_pos.x = point.x;
+    this->_pos.y = point.y;
+    
+    std::ostringstream gcode;
+    gcode << "G1 X" << XYZF_NUM(point.x)
+          <<   " Y" << XYZF_NUM(point.y)
+          <<   " F" << XYZF_NUM(this->config.travel_speed.value * 60.0);
+    COMMENT(comment);
+    gcode << "\n";
+    return gcode.str();
+}
+
+std::string
+GCodeWriter::travel_to_xyz(const Pointf3 &point, const std::string &comment)
+{
+    /*  If target Z is lower than current Z but higher than nominal Z we
+        don't perform the Z move but we only move in the XY plane and
+        adjust the nominal Z by reducing the lift amount that will be 
+        used for unlift. */
+    if (!this->will_move_z(point.z)) {
+        double nominal_z = this->_pos.z - this->_lifted;
+        this->_lifted = this->_lifted - (point.z - nominal_z);
+        return this->travel_to_xy(point);
+    }
+    
+    /*  In all the other cases, we perform an actual XYZ move and cancel
+        the lift. */
+    this->_lifted = 0;
+    this->_pos = point;
+    
+    std::ostringstream gcode;
+    gcode << "G1 X" << XYZF_NUM(point.x)
+          <<   " Y" << XYZF_NUM(point.y)
+          <<   " Z" << XYZF_NUM(point.z)
+          <<   " F" << XYZF_NUM(this->config.travel_speed.value * 60.0);
+    COMMENT(comment);
+    gcode << "\n";
+    return gcode.str();
+}
+
+std::string
+GCodeWriter::travel_to_z(double z, const std::string &comment)
+{
+    /*  If target Z is lower than current Z but higher than nominal Z
+        we don't perform the move but we only adjust the nominal Z by
+        reducing the lift amount that will be used for unlift. */
+    if (!this->will_move_z(z)) {
+        double nominal_z = this->_pos.z - this->_lifted;
+        this->_lifted = this->_lifted - (z - nominal_z);
+        return "";
+    }
+    
+    /*  In all the other cases, we perform an actual Z move and cancel
+        the lift. */
+    this->_lifted = 0;
+    return this->_travel_to_z(z, comment);
+}
+
+std::string
+GCodeWriter::_travel_to_z(double z, const std::string &comment)
+{
+    this->_pos.z = z;
+    
+    std::ostringstream gcode;
+    gcode << "G1 Z" << XYZF_NUM(z)
+          <<   " F" << XYZF_NUM(this->config.travel_speed.value * 60.0);
+    COMMENT(comment);
+    gcode << "\n";
+    return gcode.str();
+}
+
+bool
+GCodeWriter::will_move_z(double z) const
+{
+    /* If target Z is lower than current Z but higher than nominal Z
+        we don't perform an actual Z move. */
+    if (this->_lifted > 0) {
+        double nominal_z = this->_pos.z - this->_lifted;
+        if (z >= nominal_z && z <= this->_pos.z)
+            return false;
+    }
+    return true;
+}
+
+std::string
+GCodeWriter::extrude_to_xy(const Pointf &point, double dE, const std::string &comment)
+{
+    this->_pos.x = point.x;
+    this->_pos.y = point.y;
+    this->_extruder->extrude(dE);
+    
+    std::ostringstream gcode;
+    gcode << "G1 X" << XYZF_NUM(point.x)
+          <<   " Y" << XYZF_NUM(point.y)
+          <<    " " << this->_extrusion_axis << E_NUM(this->_extruder->E);
+    COMMENT(comment);
+    gcode << "\n";
+    return gcode.str();
+}
+
+std::string
+GCodeWriter::extrude_to_xyz(const Pointf3 &point, double dE, const std::string &comment)
+{
+    this->_pos = point;
+    this->_lifted = 0;
+    this->_extruder->extrude(dE);
+    
+    std::ostringstream gcode;
+    gcode << "G1 X" << XYZF_NUM(point.x)
+          <<   " Y" << XYZF_NUM(point.y)
+          <<   " Z" << XYZF_NUM(point.z)
+          <<    " " << this->_extrusion_axis << E_NUM(this->_extruder->E);
+    COMMENT(comment);
+    gcode << "\n";
+    return gcode.str();
+}
+
+std::string
+GCodeWriter::retract()
+{
+    return this->_retract(
+        this->_extruder->retract_length(),
+        this->_extruder->retract_restart_extra(),
+        "retract"
+    );
+}
+
+std::string
+GCodeWriter::retract_for_toolchange()
+{
+    return this->_retract(
+        this->_extruder->retract_length_toolchange(),
+        this->_extruder->retract_restart_extra_toolchange(),
+        "retract for toolchange"
+    );
+}
+
+std::string
+GCodeWriter::_retract(double length, double restart_extra, const std::string &comment)
+{
+    std::ostringstream gcode;
+    double dE = this->_extruder->retract(length, restart_extra);
+    if (dE != 0) {
+        if (this->config.use_firmware_retraction) {
+            gcode << "G10 ; retract\n";
+        } else {
+            gcode << "G1 " << this->_extrusion_axis << E_NUM(this->_extruder->E)
+                           << " F" << this->_extruder->retract_speed_mm_min;
+            COMMENT(comment);
+            gcode << "\n";
+        }
+    }
+    
+    if (FLAVOR_IS(gcfMakerWare))
+        gcode << "M103 ; extruder off\n";
+    
+    return gcode.str();
+}
+
+std::string
+GCodeWriter::unretract()
+{
+    std::ostringstream gcode;
+    
+    if (FLAVOR_IS(gcfMakerWare))
+        gcode << "M101 ; extruder on\n";
+    
+    double dE = this->_extruder->unretract();
+    if (dE != 0) {
+        if (this->config.use_firmware_retraction) {
+            gcode << "G11 ; unretract\n";
+            gcode << this->reset_e();
+        } else {
+            // use G1 instead of G0 because G0 will blend the restart with the previous travel move
+            gcode << "G1 " << this->_extrusion_axis << E_NUM(this->_extruder->E)
+                           << " F" << this->_extruder->retract_speed_mm_min;
+            if (this->config.gcode_comments) gcode << " ; unretract";
+            gcode << "\n";
+        }
+    }
+    
+    return gcode.str();
+}
+
+/*  If this method is called more than once before calling unlift(),
+    it will not perform subsequent lifts, even if Z was raised manually
+    (i.e. with travel_to_z()) and thus _lifted was reduced. */
+std::string
+GCodeWriter::lift()
+{
+    double target_lift = this->config.retract_lift.get_at(0);
+    if (this->_lifted == 0 && target_lift > 0) {
+        this->_lifted = target_lift;
+        return this->_travel_to_z(this->_pos.z + target_lift, "lift Z");
+    }
+    return "";
+}
+
+std::string
+GCodeWriter::unlift()
+{
+    std::string gcode;
+    if (this->_lifted > 0) {
+        gcode += this->_travel_to_z(this->_pos.z - this->_lifted, "restore layer Z");
+        this->_lifted = 0;
+    }
+    return gcode;
+}
+
+#ifdef SLIC3RXS
+REGISTER_CLASS(GCodeWriter, "GCode::Writer");
+#endif
+
+}
\ No newline at end of file
diff --git a/xs/src/libslic3r/GCodeWriter.hpp b/xs/src/libslic3r/GCodeWriter.hpp
new file mode 100644
index 000000000..5500a19f5
--- /dev/null
+++ b/xs/src/libslic3r/GCodeWriter.hpp
@@ -0,0 +1,63 @@
+#ifndef slic3r_GCodeWriter_hpp_
+#define slic3r_GCodeWriter_hpp_
+
+#include <myinit.h>
+#include <string>
+#include "Extruder.hpp"
+#include "Point.hpp"
+#include "PrintConfig.hpp"
+
+namespace Slic3r {
+
+class GCodeWriter {
+    public:
+    GCodeConfig config;
+    std::map<unsigned int,Extruder> extruders;
+    bool multiple_extruders;
+    
+    GCodeWriter()
+        : multiple_extruders(false), _extrusion_axis("E"), _extruder(NULL),
+            _last_acceleration(0), _last_fan_speed(0), _lifted(0)
+        {};
+    Extruder* extruder();
+    std::string extrusion_axis() const;
+    void apply_print_config(const PrintConfig &print_config);
+    void set_extruders(const std::vector<unsigned int> &extruder_ids);
+    std::string preamble();
+    std::string set_temperature(unsigned int temperature, bool wait = false, int tool = -1);
+    std::string set_bed_temperature(unsigned int temperature, bool wait = false);
+    std::string set_fan(unsigned int speed, bool dont_save = false);
+    std::string set_acceleration(unsigned int acceleration);
+    std::string reset_e(bool force = false);
+    std::string update_progress(unsigned int num, unsigned int tot, bool allow_100 = false);
+    bool need_toolchange(unsigned int extruder_id) const;
+    std::string set_extruder(unsigned int extruder_id);
+    std::string toolchange(unsigned int extruder_id);
+    std::string set_speed(double F, const std::string &comment = std::string());
+    std::string travel_to_xy(const Pointf &point, const std::string &comment = std::string());
+    std::string travel_to_xyz(const Pointf3 &point, const std::string &comment = std::string());
+    std::string travel_to_z(double z, const std::string &comment = std::string());
+    bool will_move_z(double z) const;
+    std::string extrude_to_xy(const Pointf &point, double dE, const std::string &comment = std::string());
+    std::string extrude_to_xyz(const Pointf3 &point, double dE, const std::string &comment = std::string());
+    std::string retract();
+    std::string retract_for_toolchange();
+    std::string unretract();
+    std::string lift();
+    std::string unlift();
+    
+    private:
+    std::string _extrusion_axis;
+    Extruder* _extruder;
+    unsigned int _last_acceleration;
+    unsigned int _last_fan_speed;
+    double _lifted;
+    Pointf3 _pos;
+    
+    std::string _travel_to_z(double z, const std::string &comment);
+    std::string _retract(double length, double restart_extra, const std::string &comment);
+};
+
+}
+
+#endif
diff --git a/xs/xsp/GCodeWriter.xsp b/xs/xsp/GCodeWriter.xsp
new file mode 100644
index 000000000..ee9049e56
--- /dev/null
+++ b/xs/xsp/GCodeWriter.xsp
@@ -0,0 +1,63 @@
+%module{Slic3r::XS};
+
+%{
+#include <myinit.h>
+#include "libslic3r/GCodeWriter.hpp"
+%}
+
+%name{Slic3r::GCode::Writer} class GCodeWriter {
+    GCodeWriter();
+    ~GCodeWriter();
+    
+    Ref<GCodeConfig> config()
+        %code%{ RETVAL = &THIS->config; %};
+    bool multiple_extruders()
+        %code{% RETVAL = THIS->multiple_extruders; %};
+    Ref<Extruder> extruder();
+    std::string extrusion_axis();
+    void apply_print_config(PrintConfig* print_config)
+        %code{% THIS->apply_print_config(*print_config); %};
+    void set_extruders(std::vector<unsigned int> extruder_ids);
+    std::string preamble();
+    std::string set_temperature(unsigned int temperature, bool wait = false, int tool = -1);
+    std::string set_bed_temperature(unsigned int temperature, bool wait = false);
+    std::string set_fan(unsigned int speed, bool dont_save = false);
+    std::string set_acceleration(unsigned int acceleration);
+    std::string reset_e(bool force = false);
+    std::string update_progress(unsigned int num, unsigned int tot, bool allow_100 = false);
+    bool need_toolchange(unsigned int extruder_id);
+    std::string set_extruder(unsigned int extruder_id);
+    std::string toolchange(unsigned int extruder_id);
+    std::string set_speed(double F, std::string comment = std::string());
+    std::string travel_to_xy(Pointf* point, std::string comment = std::string())
+        %code{% RETVAL = THIS->travel_to_xy(*point, comment); %};
+    std::string travel_to_xyz(Pointf3* point, std::string comment = std::string())
+        %code{% RETVAL = THIS->travel_to_xyz(*point, comment); %};
+    std::string travel_to_z(double z, std::string comment = std::string());
+    bool will_move_z(double z);
+    std::string extrude_to_xy(Pointf* point, double dE, std::string comment = std::string())
+        %code{% RETVAL = THIS->extrude_to_xy(*point, dE, comment); %};
+    std::string extrude_to_xyz(Pointf3* point, double dE, std::string comment = std::string())
+        %code{% RETVAL = THIS->extrude_to_xyz(*point, dE, comment); %};
+    std::string retract();
+    std::string retract_for_toolchange();
+    std::string unretract();
+    std::string lift();
+    std::string unlift();
+%{
+
+SV*
+GCodeWriter::extruders()
+    CODE:
+        AV* av = newAV();
+        av_fill(av, THIS->extruders.size()-1);
+        int i = 0;
+        for (std::map<unsigned int,Extruder>::iterator it = THIS->extruders.begin(); it != THIS->extruders.end(); ++it) {
+            av_store(av, i++, perl_to_SV_ref(it->second));
+        }
+        RETVAL = newRV_noinc((SV*)av);
+    OUTPUT:
+        RETVAL
+
+%}
+};
diff --git a/xs/xsp/my.map b/xs/xsp/my.map
index 41476ca2c..8429f3ee7 100644
--- a/xs/xsp/my.map
+++ b/xs/xsp/my.map
@@ -111,6 +111,8 @@ SurfaceCollection*         O_OBJECT_SLIC3R
 Ref<SurfaceCollection>     O_OBJECT_SLIC3R_T
 
 Extruder*                  O_OBJECT_SLIC3R
+Ref<Extruder>              O_OBJECT_SLIC3R_T
+Clone<Extruder>            O_OBJECT_SLIC3R_T
 
 Model*                     O_OBJECT_SLIC3R
 Ref<Model>                 O_OBJECT_SLIC3R_T
@@ -159,6 +161,10 @@ MotionPlanner*             O_OBJECT_SLIC3R
 Ref<MotionPlanner>         O_OBJECT_SLIC3R_T
 Clone<MotionPlanner>       O_OBJECT_SLIC3R_T
 
+GCodeWriter*               O_OBJECT_SLIC3R
+Ref<GCodeWriter>           O_OBJECT_SLIC3R_T
+Clone<GCodeWriter>         O_OBJECT_SLIC3R_T
+
 ExtrusionLoopRole     T_UV
 ExtrusionRole     T_UV
 FlowRole     T_UV
diff --git a/xs/xsp/typemap.xspt b/xs/xsp/typemap.xspt
index 01718a8cb..351e1ccd8 100644
--- a/xs/xsp/typemap.xspt
+++ b/xs/xsp/typemap.xspt
@@ -9,6 +9,8 @@
 %typemap{std::vector<unsigned int>*};
 %typemap{std::vector<double>};
 %typemap{std::vector<double>*};
+%typemap{std::vector<unsigned int>};
+%typemap{std::vector<unsigned int>*};
 %typemap{std::vector<std::string>};
 %typemap{t_layer_height_ranges};
 %typemap{SV*};
@@ -82,6 +84,9 @@
 %typemap{MotionPlanner*};
 %typemap{Ref<MotionPlanner>}{simple};
 %typemap{Clone<MotionPlanner>}{simple};
+%typemap{GCodeWriter*};
+%typemap{Ref<GCodeWriter>}{simple};
+%typemap{Clone<GCodeWriter>}{simple};
 
 %typemap{Surface*};
 %typemap{Ref<Surface>}{simple};
@@ -127,6 +132,8 @@
 %typemap{TriangleMeshPtrs};
 %typemap{Ref<SurfaceCollection>}{simple};
 %typemap{Extruder*};
+%typemap{Ref<Extruder>}{simple};
+%typemap{Clone<Extruder>}{simple};
 %typemap{Model*};
 %typemap{Ref<Model>}{simple};
 %typemap{Clone<Model>}{simple};