diff --git a/resources/localization/en_US/Slic3rPE.mo b/resources/localization/en_US/Slic3rPE.mo
new file mode 100644
index 000000000..46e2c85b9
Binary files /dev/null and b/resources/localization/en_US/Slic3rPE.mo differ
diff --git a/resources/localization/uk/Slic3rPE.mo b/resources/localization/uk/Slic3rPE.mo
new file mode 100644
index 000000000..82aa2e48e
Binary files /dev/null and b/resources/localization/uk/Slic3rPE.mo differ
diff --git a/xs/src/libslic3r/Utils.hpp b/xs/src/libslic3r/Utils.hpp
index fd60cf91a..d49995f95 100644
--- a/xs/src/libslic3r/Utils.hpp
+++ b/xs/src/libslic3r/Utils.hpp
@@ -19,6 +19,8 @@ std::string var(const std::string &file_name);
 void set_resources_dir(const std::string &path);
 // Return a full path to the resources directory.
 const std::string& resources_dir();
+// Return a full path to the localization directory.
+std::string localization_dir();
 
 // Set a path with preset files.
 void set_data_dir(const std::string &path);
diff --git a/xs/src/libslic3r/utils.cpp b/xs/src/libslic3r/utils.cpp
index 1a7e16f11..7cd82f931 100644
--- a/xs/src/libslic3r/utils.cpp
+++ b/xs/src/libslic3r/utils.cpp
@@ -103,6 +103,11 @@ const std::string& resources_dir()
     return g_resources_dir;
 }
 
+std::string localization_dir()
+{
+	return resources_dir() + "\\localization\\";
+}
+
 static std::string g_data_dir;
 
 void set_data_dir(const std::string &dir)
diff --git a/xs/src/slic3r/GUI/BedShapeDialog.cpp b/xs/src/slic3r/GUI/BedShapeDialog.cpp
index 5903b8ec6..591188443 100644
--- a/xs/src/slic3r/GUI/BedShapeDialog.cpp
+++ b/xs/src/slic3r/GUI/BedShapeDialog.cpp
@@ -11,16 +11,15 @@
 #include <wx/config.h>
 #include <wx/dir.h>
 #include <wx/filename.h>
+#include "Utils.hpp"
 
 namespace Slic3r {
 namespace GUI {
 
-//! macro used to localization
-#define _L(s) s
-
 void BedShapeDialog::build_dialog(ConfigOptionPoints* default_pt)
 {
 	m_App = get_app();
+	LoadLanguage();
 	m_panel = new BedShapePanel(this);
 	m_panel->build_panel(default_pt);
 
@@ -56,14 +55,14 @@ bool BedShapeDialog::LoadLanguage()
 	{
 		if (identifiers[i] == language)
 		{
-			if (m_Locale) wxDELETE(m_Locale);
-			m_Locale = new wxLocale;
+ 			m_Locale = new wxLocale;
 			m_Locale->Init(identifiers[i]);
-			m_Locale->AddCatalogLookupPathPrefix(wxPathOnly(m_App->argv[0]));
+			m_Locale->AddCatalogLookupPathPrefix(wxPathOnly(m_local_dir));
 			m_Locale->AddCatalog(m_App->GetAppName());
 			return true;
 		}
 	}
+	return false;
 }
 
 void BedShapeDialog::GetInstalledLanguages(wxArrayString & names,
@@ -71,7 +70,9 @@ void BedShapeDialog::GetInstalledLanguages(wxArrayString & names,
 {
 	names.Clear();
 	identifiers.Clear();
-	wxDir dir(wxPathOnly(m_App->argv[0]));
+	m_local_dir = localization_dir();
+
+	wxDir dir(wxPathOnly(m_local_dir));
 	wxString filename;
 	const wxLanguageInfo * langinfo;
 	wxString name = wxLocale::GetLanguageName(wxLANGUAGE_DEFAULT);
@@ -80,7 +81,7 @@ void BedShapeDialog::GetInstalledLanguages(wxArrayString & names,
 		names.Add(_L("Default"));
 		identifiers.Add(wxLANGUAGE_DEFAULT);
 	}
-	for (bool cont = dir.GetFirst(&filename, wxT("*.*"), wxDIR_DIRS);
+	for (bool cont = dir.GetFirst(&filename, wxEmptyString/*wxT("*.*")*/, wxDIR_DIRS);
 		cont; cont = dir.GetNext(&filename))
 	{
 		wxLogTrace(wxTraceMask(),
@@ -89,9 +90,10 @@ void BedShapeDialog::GetInstalledLanguages(wxArrayString & names,
 		langinfo = wxLocale::FindLanguageInfo(filename);
 		if (langinfo != NULL)
 		{
-			if (wxFileExists(dir.GetName() + wxFileName::GetPathSeparator() +
+			auto full_file_name = dir.GetName() + wxFileName::GetPathSeparator() +
 				filename + wxFileName::GetPathSeparator() +
-				m_App->GetAppName() + wxT(".mo")))
+				m_App->GetAppName() + wxT(".mo");
+			if (wxFileExists(full_file_name))
 			{
 				names.Add(langinfo->Description);
 				identifiers.Add(langinfo->Language);
@@ -104,7 +106,6 @@ void BedShapePanel::build_panel(ConfigOptionPoints* default_pt)
 {
 //	on_change(nullptr);
 
-//	auto box = new wxStaticBox(this, wxID_ANY, "Shape");
 	auto box = new wxStaticBox(this, wxID_ANY, _L("Shape"));
 	auto sbsizer = new wxStaticBoxSizer(box, wxVERTICAL);
 
@@ -112,31 +113,28 @@ void BedShapePanel::build_panel(ConfigOptionPoints* default_pt)
 	m_shape_options_book = new wxChoicebook(this, wxID_ANY, wxDefaultPosition, wxSize(300, -1), wxCHB_TOP);
 	sbsizer->Add(m_shape_options_book);
 
-//	auto optgroup = init_shape_options_page("Rectangular");
 	auto optgroup = init_shape_options_page(_L("Rectangular"));
 		ConfigOptionDef def;
 		def.type = coPoints;
 		def.default_value = new ConfigOptionPoints{ Pointf(200, 200) };
-// 		def.label = "Size";
-// 		def.tooltip = "Size in X and Y of the rectangular plate.";
-		def.label = _L("Size");
-		def.tooltip = _L("Size in X and Y of the rectangular plate.");
+		def.label = _LU8("Size");
+		def.tooltip = _LU8("Size in X and Y of the rectangular plate.");
 		Option option(def, "rect_size");
 		optgroup->append_single_option_line(option);
 
 		def.type = coPoints;
 		def.default_value = new ConfigOptionPoints{ Pointf(0, 0) };
-		def.label = _L("Origin");
-		def.tooltip = _L("Distance of the 0,0 G-code coordinate from the front left corner of the rectangle.");
+		def.label = _LU8("Origin");
+		def.tooltip = _LU8("Distance of the 0,0 G-code coordinate from the front left corner of the rectangle.");
 		option = Option(def, "rect_origin");
 		optgroup->append_single_option_line(option);
 
 		optgroup = init_shape_options_page(_L("Circular"));
 		def.type = coFloat;
 		def.default_value = new ConfigOptionFloat(200);
-		def.sidetext = _L("mm");
-		def.label = _L("Diameter");
-		def.tooltip = _L("Diameter of the print bed. It is assumed that origin (0,0) is located in the center.");
+		def.sidetext = _LU8("mm");
+		def.label = _LU8("Diameter");
+		def.tooltip = _LU8("Diameter of the print bed. It is assumed that origin (0,0) is located in the center.");
 		option = Option(def, "diameter");
 		optgroup->append_single_option_line(option);
 
@@ -185,7 +183,7 @@ void BedShapePanel::build_panel(ConfigOptionPoints* default_pt)
 
 // Called from the constructor.
 // Create a panel for a rectangular / circular / custom bed shape.
-ConfigOptionsGroupShp BedShapePanel::init_shape_options_page(std::string title){
+ConfigOptionsGroupShp BedShapePanel::init_shape_options_page(wxString title){
 
 	auto panel = new wxPanel(m_shape_options_book);
 	ConfigOptionsGroupShp optgroup;
diff --git a/xs/src/slic3r/GUI/BedShapeDialog.hpp b/xs/src/slic3r/GUI/BedShapeDialog.hpp
index 606c8013c..5bd7d68b9 100644
--- a/xs/src/slic3r/GUI/BedShapeDialog.hpp
+++ b/xs/src/slic3r/GUI/BedShapeDialog.hpp
@@ -25,7 +25,7 @@ public:
 
 	void		build_panel(ConfigOptionPoints* default_pt);
 	
-	ConfigOptionsGroupShp	init_shape_options_page(std::string title);
+	ConfigOptionsGroupShp	init_shape_options_page(wxString title);
 	void		set_shape(ConfigOptionPoints* points);
 	void		update_preview();
 	void		update_shape();
@@ -40,10 +40,11 @@ class BedShapeDialog : public wxDialog
 	BedShapePanel*	m_panel;
 	wxLocale*		m_Locale;
 	wxApp*			m_App;
+	std::string		m_local_dir;
 public:
-	BedShapeDialog(wxWindow* parent) : wxDialog(parent, wxID_ANY, "Bed Shape",
+	BedShapeDialog(wxWindow* parent) : wxDialog(parent, wxID_ANY, _L("Bed Shape"),
 		wxDefaultPosition, wxSize(350, 700), wxDEFAULT_DIALOG_STYLE | wxRESIZE_BORDER){}
-	~BedShapeDialog(){ if (m_Locale){ wxDELETE(m_Locale);} }
+	~BedShapeDialog(){  }
 
 	void		build_dialog(ConfigOptionPoints* default_pt);
 	std::vector<Pointf>	GetValue() { return m_panel->GetValue(); }
diff --git a/xs/src/slic3r/GUI/Field.cpp b/xs/src/slic3r/GUI/Field.cpp
index 96350fcb4..291a83e4f 100644
--- a/xs/src/slic3r/GUI/Field.cpp
+++ b/xs/src/slic3r/GUI/Field.cpp
@@ -30,10 +30,11 @@ namespace Slic3r { namespace GUI {
 	wxString Field::get_tooltip_text(const wxString& default_string)
 	{
 		wxString tooltip_text("");
-		if (m_opt.tooltip.length() > 0)
+		wxString tooltip = wxString::FromUTF8(m_opt.tooltip.c_str());
+		if (tooltip.length() > 0)
 			tooltip_text = boost::iends_with(m_opt_id, "_gcode") ?
-						m_opt.tooltip + "(default: \n" + default_string + ")" : 
-						m_opt.tooltip + "(default: " + default_string + ")";
+						tooltip + "(" + _L("default") + ": \n" + default_string + ")" : 
+						tooltip + "(" + _L("default") + ": " + default_string + ")";
 
 		return tooltip_text;
 	}
diff --git a/xs/src/slic3r/GUI/GUI.cpp b/xs/src/slic3r/GUI/GUI.cpp
index 87bae567f..624962002 100644
--- a/xs/src/slic3r/GUI/GUI.cpp
+++ b/xs/src/slic3r/GUI/GUI.cpp
@@ -195,12 +195,6 @@ void create_preset_tabs(PresetBundle *preset_bundle, AppConfig *app_config,
 	add_created_tab(new TabFilament	(g_wxTabPanel, no_controller), preset_bundle, app_config);
 	add_created_tab(new TabPrinter	(g_wxTabPanel, no_controller, is_disabled_button_browse, is_user_agent), 
 					preset_bundle, app_config);
-// 	g_wxTabPanel->Bind(wxEVT_NOTEBOOK_PAGE_CHANGED, ([](wxCommandEvent e){
-// 		Tab* panel = (Tab*)g_wxTabPanel->GetCurrentPage();
-// 		if (panel->GetName().compare("Print Settings")==0 ||
-// 			panel->GetName().compare("Filament Settings") == 0)
-// 			panel->OnActivate();
-// 	}), g_wxTabPanel->GetId() );
 	for (size_t i = 0; i < g_wxTabPanel->GetPageCount(); ++ i) {
 		Tab *tab = dynamic_cast<Tab*>(g_wxTabPanel->GetPage(i));
 		if (! tab)
@@ -320,12 +314,12 @@ void add_created_tab(Tab* panel, PresetBundle *preset_bundle, AppConfig *app_con
 	g_wxTabPanel->AddPage(panel, panel->title());
 }
 
-void show_error(wxWindow* parent, std::string message){
+void show_error(wxWindow* parent, wxString message){
 	auto msg_wingow = new wxMessageDialog(parent, message, "Error", wxOK | wxICON_ERROR);
 	msg_wingow->ShowModal();
 }
 
-void show_info(wxWindow* parent, std::string message, std::string title){
+void show_info(wxWindow* parent, wxString message, wxString title){
 	auto msg_wingow = new wxMessageDialog(parent, message, title.empty() ? "Notice" : title, wxOK | wxICON_INFORMATION);
 	msg_wingow->ShowModal();
 }
diff --git a/xs/src/slic3r/GUI/GUI.hpp b/xs/src/slic3r/GUI/GUI.hpp
index 5f087e41a..cc6bae964 100644
--- a/xs/src/slic3r/GUI/GUI.hpp
+++ b/xs/src/slic3r/GUI/GUI.hpp
@@ -10,6 +10,7 @@ class wxFrame;
 class wxWindow;
 class wxMenuBar;
 class wxNotebook;
+class wxString;
 
 namespace Slic3r { 
 
@@ -19,6 +20,11 @@ class AppConfig;
 class DynamicPrintConfig;
 class TabIface;
 
+//! macro used to localization, return wxString
+#define _L(s) wxGetTranslation(s)
+//! macro used to localization, return const CharType *
+#define _LU8(s) wxGetTranslation(s).ToUTF8().data()
+
 namespace GUI {
 
 class Tab;
@@ -63,8 +69,8 @@ void add_created_tab(Tab* panel, PresetBundle *preset_bundle, AppConfig *app_con
 // Change option value in config
 void change_opt_value(DynamicPrintConfig& config, t_config_option_key opt_key, boost::any value);
 
-void show_error(wxWindow* parent, std::string message);
-void show_info(wxWindow* parent, std::string message, std::string title);
+void show_error(wxWindow* parent, wxString message);
+void show_info(wxWindow* parent, wxString message, wxString title);
 
 wxApp* get_app();
 
diff --git a/xs/src/slic3r/GUI/OptionsGroup.cpp b/xs/src/slic3r/GUI/OptionsGroup.cpp
index 7f3b4ee66..46f395e5c 100644
--- a/xs/src/slic3r/GUI/OptionsGroup.cpp
+++ b/xs/src/slic3r/GUI/OptionsGroup.cpp
@@ -112,12 +112,13 @@ void OptionsGroup::append_line(const Line& line) {
 
     // Build a label if we have it
     if (label_width != 0) {
-		auto label = new wxStaticText(parent(), wxID_ANY, line.label + (line.label.IsEmpty() ? "" : ":" ), wxDefaultPosition, wxSize(label_width, -1));
+		auto label = new wxStaticText(parent(), wxID_ANY, line.label + (line.label.IsEmpty() ? "" : ":"), 
+							wxDefaultPosition, wxSize(label_width, -1));
         label->SetFont(label_font);
         label->Wrap(label_width); // avoid a Linux/GTK bug
         grid_sizer->Add(label, 0, wxALIGN_CENTER_VERTICAL,0);
-        if (line.label_tooltip.compare("") != 0)
-            label->SetToolTip(line.label_tooltip);
+		if (line.label_tooltip.compare("") != 0)
+			label->SetToolTip(line.label_tooltip);
     }
 
     // If there's a widget, build it and add the result to the sizer.
@@ -151,7 +152,7 @@ void OptionsGroup::append_line(const Line& line) {
 		ConfigOptionDef option = opt.opt;
 		// add label if any
 		if (option.label != "") {
-			auto field_label = new wxStaticText(parent(), wxID_ANY, wxString(option.label) + ":", wxDefaultPosition, wxDefaultSize);
+			auto field_label = new wxStaticText(parent(), wxID_ANY, wxString::FromUTF8(option.label.c_str()) + ":", wxDefaultPosition, wxDefaultSize);
 			field_label->SetFont(sidetext_font);
 			sizer->Add(field_label, 0, wxALIGN_CENTER_VERTICAL, 0);
 		}
@@ -187,7 +188,7 @@ void OptionsGroup::append_line(const Line& line) {
 }
 
 Line OptionsGroup::create_single_option_line(const Option& option) const {
-    Line retval {option.opt.label, option.opt.tooltip};	
+	Line retval{ wxString::FromUTF8(option.opt.label.c_str()), wxString::FromUTF8(option.opt.tooltip.c_str()) };
     Option tmp(option);
     tmp.opt.label = std::string("");
     retval.append_option(tmp);
diff --git a/xs/src/slic3r/GUI/OptionsGroup.hpp b/xs/src/slic3r/GUI/OptionsGroup.hpp
index 42b0b5344..0e54de70c 100644
--- a/xs/src/slic3r/GUI/OptionsGroup.hpp
+++ b/xs/src/slic3r/GUI/OptionsGroup.hpp
@@ -54,8 +54,8 @@ public:
 	void append_widget(const widget_t widget) {
 		m_extra_widgets.push_back(widget);
     }
-    Line(std::string label, std::string tooltip) : 
-		label(wxString(label)), label_tooltip(wxString(tooltip)) {}
+	Line(wxString label, wxString tooltip) :
+		label(label), label_tooltip(tooltip) {}
 
     const std::vector<widget_t>&	get_extra_widgets() const {return m_extra_widgets;}
     const std::vector<Option>&		get_options() const { return m_options; }
@@ -96,8 +96,8 @@ public:
 	inline void		enable() { for (auto& field : m_fields) field.second->enable(); }
     inline void		disable() { for (auto& field : m_fields) field.second->disable(); }
 
-    OptionsGroup(wxWindow* _parent, std::string title) : 
-		m_parent(_parent), title(wxString(title)) {
+    OptionsGroup(wxWindow* _parent, wxString title) : 
+		m_parent(_parent), title(title) {
         sizer = (staticbox ? new wxStaticBoxSizer(new wxStaticBox(_parent, wxID_ANY, title), wxVERTICAL) : new wxBoxSizer(wxVERTICAL));
         auto num_columns = 1U;
         if (label_width != 0) num_columns++;
@@ -133,7 +133,7 @@ protected:
 
 class ConfigOptionsGroup: public OptionsGroup {
 public:
-	ConfigOptionsGroup(wxWindow* parent, std::string title, DynamicPrintConfig* _config = nullptr) : 
+	ConfigOptionsGroup(wxWindow* parent, wxString title, DynamicPrintConfig* _config = nullptr) : 
 		OptionsGroup(parent, title), m_config(_config) {}
 
     /// reference to libslic3r config, non-owning pointer (?).
diff --git a/xs/src/slic3r/GUI/Tab.cpp b/xs/src/slic3r/GUI/Tab.cpp
index bb8858296..9b25f2444 100644
--- a/xs/src/slic3r/GUI/Tab.cpp
+++ b/xs/src/slic3r/GUI/Tab.cpp
@@ -1735,7 +1735,7 @@ bool Page::set_value(t_config_option_key opt_key, boost::any value){
 }
 
 // package Slic3r::GUI::Tab::Page;
-ConfigOptionsGroupShp Page::new_optgroup(std::string title, int noncommon_label_width /*= -1*/)
+ConfigOptionsGroupShp Page::new_optgroup(wxString title, int noncommon_label_width /*= -1*/)
 {
 	//! config_ have to be "right"
 	ConfigOptionsGroupShp optgroup = std::make_shared<ConfigOptionsGroup>(this, title, m_config);
diff --git a/xs/src/slic3r/GUI/Tab.hpp b/xs/src/slic3r/GUI/Tab.hpp
index ab0df4629..03cb0ad50 100644
--- a/xs/src/slic3r/GUI/Tab.hpp
+++ b/xs/src/slic3r/GUI/Tab.hpp
@@ -55,7 +55,7 @@ public:
 	~Page(){}
 
 public:
-	std::vector <ConfigOptionsGroupShp> m_optgroups;  // $self->{optgroups} = [];
+	std::vector <ConfigOptionsGroupShp> m_optgroups;
 	DynamicPrintConfig* m_config;
 
 	wxBoxSizer*	vsizer() const { return m_vsizer; }
@@ -66,7 +66,7 @@ public:
 	void		reload_config();
 	Field*		get_field(t_config_option_key opt_key, int opt_index = -1) const;
 	bool		set_value(t_config_option_key opt_key, boost::any value);
-	ConfigOptionsGroupShp new_optgroup(std::string title, int noncommon_label_width = -1);
+	ConfigOptionsGroupShp	new_optgroup(wxString title, int noncommon_label_width = -1);
 };
 
 // Slic3r::GUI::Tab;
diff --git a/xs/src/slic3r/GUI/TabIface.cpp b/xs/src/slic3r/GUI/TabIface.cpp
index 27d62b044..2b897a7b9 100644
--- a/xs/src/slic3r/GUI/TabIface.cpp
+++ b/xs/src/slic3r/GUI/TabIface.cpp
@@ -7,11 +7,11 @@ void	TabIface::load_current_preset()		{ m_tab->load_current_preset(); }
 void	TabIface::update_tab_ui()			{ m_tab->update_tab_ui(); }
 void	TabIface::update_ui_from_settings()	{ m_tab->update_ui_from_settings();}
 void	TabIface::select_preset(char* name)	{ m_tab->select_preset(name);}
-char*	TabIface::title()					{ return (char*)m_tab->title().ToStdString().data();}
 void	TabIface::load_config(DynamicPrintConfig* config)	{ m_tab->load_config(*config);}
 void	TabIface::load_key_value(char* opt_key, char* value){ m_tab->load_key_value(opt_key, static_cast<std::string>(value)); }
 bool	TabIface::current_preset_is_dirty()					{ return m_tab->current_preset_is_dirty();}
 void	TabIface::OnActivate()								{ return m_tab->OnActivate();}
+std::string					TabIface::title()				{ return m_tab->title().ToStdString();}
 DynamicPrintConfig*			TabIface::get_config()			{ return m_tab->get_config(); }
 PresetCollection*			TabIface::get_presets()			{ return m_tab->get_presets(); }
 std::vector<std::string>	TabIface::get_dependent_tabs()	{ return m_tab->get_dependent_tabs(); }
diff --git a/xs/src/slic3r/GUI/TabIface.hpp b/xs/src/slic3r/GUI/TabIface.hpp
index cba2c2ed1..0325c855c 100644
--- a/xs/src/slic3r/GUI/TabIface.hpp
+++ b/xs/src/slic3r/GUI/TabIface.hpp
@@ -19,7 +19,7 @@ public:
 	void		update_tab_ui();
 	void		update_ui_from_settings();
 	void		select_preset(char* name);
-	char*		title();
+	std::string title();
 	void		load_config(DynamicPrintConfig* config);
 	void		load_key_value(char* opt_key, char* value);
 	bool		current_preset_is_dirty();
diff --git a/xs/xsp/GUI_Tab.xsp b/xs/xsp/GUI_Tab.xsp
index 35e1cb9e6..f38d63143 100644
--- a/xs/xsp/GUI_Tab.xsp
+++ b/xs/xsp/GUI_Tab.xsp
@@ -15,8 +15,8 @@
 	void		load_config(DynamicPrintConfig* config);
 	bool		current_preset_is_dirty();
 	void		load_key_value(char* opt_key, char* value);
-	char*		title();
 	void		OnActivate();
+	std::string	title();
 	Ref<DynamicPrintConfig>		get_config();
 	Ref<PresetCollection>		get_presets();
 	std::vector<std::string>	get_dependent_tabs();