diff --git a/Makefile.am b/Makefile.am
index 5870425..d6cea4d 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -181,6 +181,7 @@ src_backend_libbackend_la_SOURCES = \
 		src/backend/schedulable.cc \
 		src/backend/scheduler.cc \
 		src/backend/serialize_visitor.cc \
+		src/backend/serializers_gatekeeper.cc \
 		src/backend/simulation.cc \
 		src/backend/static_process.cc \
 		src/backend/static_request.cc \
@@ -221,7 +222,8 @@ pkginclude_HEADERS += \
 		src/backend/process.hh \
 		src/backend/schedulable.hh \
 		src/backend/scheduler.hh \
-		src/backend/serialize_visitor.cc \
+		src/backend/serialize_visitor.hh \
+		src/backend/serializers_gatekeeper.hh \
 		src/backend/simulation.hh \
 		src/backend/sub_request.hh \
 		src/backend/thread.hh \
diff --git a/plugins/xmlsave/Makefile.am b/plugins/xmlsave/Makefile.am
index b708596..ba3b9e4 100644
--- a/plugins/xmlsave/Makefile.am
+++ b/plugins/xmlsave/Makefile.am
@@ -88,9 +88,15 @@ libxmlsave_la_LDFLAGS = \
 
 # Please keep this in sorted order:
 libxmlsave_la_SOURCES = \
-               src/plugin.cc
+               src/plugin.cc \
+	       src/xml_serializer.cc \
+	       src/xml_serializer_factory.cc \
+	       src/xml_visitor.cc
 
-noinst_HEADERS += 
+noinst_HEADERS += \
+	       src/xml_serializer_factory.hh \
+	       src/xml_serializer.hh \
+	       src/xml_visitor.hh
 
 # ############################################################
 #
diff --git a/plugins/xmlsave/src/plugin.cc b/plugins/xmlsave/src/plugin.cc
index f488229..e5a421e 100644
--- a/plugins/xmlsave/src/plugin.cc
+++ b/plugins/xmlsave/src/plugin.cc
@@ -21,27 +21,30 @@
 #include "config.h"
 
 #include "plugin.hh"
+#include "xml_serializer.hh"
 
-//static XMLSerializer* _serializer = NULL;
+using namespace sgpem;
+
+sgpem::XMLSerializer* _serializer = NULL;
 
 void 
 sgpem__Plugin__on_init()
 {
-	//  if(_serializer == NULL)
-	//    _serializer = new sgpem::XMLSerializer();
+  if(_serializer == NULL)
+    _serializer = new sgpem::XMLSerializer();
 }
 
 void 
 sgpem__Plugin__on_exit()
 {
-	//  delete _serializer;
-	//  _serializer = NULL;
+  delete _serializer;
+  _serializer = NULL;
 }
 
 const char* 
 sgpem__Plugin__describe()
 {
-  return "";
+  return "This plugin saves the simulation to an XML file";
 }
 
 const char* 
diff --git a/plugins/xmlsave/src/xml_serializer.cc b/plugins/xmlsave/src/xml_serializer.cc
index 936fe4f..bccefb5 100644
--- a/plugins/xmlsave/src/xml_serializer.cc
+++ b/plugins/xmlsave/src/xml_serializer.cc
@@ -22,11 +22,11 @@
 #include "xml_serializer_factory.hh"
 #include "xml_visitor.hh"
 
-#include "backend/environment.hh"
-#include "backend/history.hh"
-#include "backend/process.hh"
-#include "backend/serializer_error.hh"
-#include "backend/string_utils.hh"
+#include "environment.hh"
+#include "history.hh"
+#include "process.hh"
+#include "serializer_error.hh"
+#include "string_utils.hh"
 
 using namespace sgpem;
 
@@ -40,7 +40,7 @@ XMLSerializer::XMLSerializer()
 
 
 
-void XMLSerializer::save_snapshot(const Glib::ustring& filename, const History& hist) throw(SerializeError)
+void XMLSerializer::save_snapshot(const Glib::ustring& filename, const History& hist) throw(SerializerError)
 {
   /* COMPAT: Do not genrate nodes for formatting spaces */
   LIBXML_TEST_VERSION
@@ -65,7 +65,7 @@ void XMLSerializer::save_snapshot(const Glib::ustring& filename, const History&
   xmlCleanupParser();
 }
 
-void XMLSerializer::restore_snapshot(const Glib::ustring& filename, History& hist) throw(SerializeError)
+void XMLSerializer::restore_snapshot(const Glib::ustring& filename, History& hist) throw(SerializerError)
 {
     // TODO - all to do!!
     // DEBUG - remove me when finished
@@ -101,7 +101,7 @@ void XMLSerializer::restore_snapshot(const Glib::ustring& filename, History& his
     /*
      * the library has been compiled without some of the old interfaces
      */
-    throw SerializerError("ERROR: Compilation with SAX1 must be enabled! (?)");
+  #error Compilation of LIBXML with SAX1 support must be enabled
 #endif /* LIBXML_SAX1_ENABLED */
 }
 
@@ -222,7 +222,7 @@ void XMLSerializer::clear_history(History& hist)
 
 }
 
-void XMLSerializer::read_doc(xmlDocPtr doc, XMLSerializerFactory& fact) throw(SerializeError)
+void XMLSerializer::read_doc(xmlDocPtr doc, XMLSerializerFactory& fact) throw(SerializerError)
 {
     /*
      * Check the document is of the right kind
diff --git a/plugins/xmlsave/src/xml_serializer.hh b/plugins/xmlsave/src/xml_serializer.hh
index 715ff41..de47820 100644
--- a/plugins/xmlsave/src/xml_serializer.hh
+++ b/plugins/xmlsave/src/xml_serializer.hh
@@ -61,7 +61,7 @@ namespace sgpem
       
       \throws backend::SerializerError on error
      */
-    virtual void save_snapshot(const Glib::ustring& filename, const History& hist) throw(SerializeError);
+    virtual void save_snapshot(const Glib::ustring& filename, const History& hist) throw(SerializerError);
 
     /**
       \brief Re-initialize system status from a saved XML snapshot
@@ -72,7 +72,7 @@ namespace sgpem
       
       \throws backend::SerializerError
      */
-    virtual void restore_snapshot(const Glib::ustring& filename, History& hist) throw(SerializeError);
+    virtual void restore_snapshot(const Glib::ustring& filename, History& hist) throw(SerializerError);
 
     /**
       \return Constant string "xsgp"
@@ -124,7 +124,7 @@ namespace sgpem
       Traverse the passed (previously readed) xml document and
       rebuild the correct image using the XMLSerializerFactory object.
      */
-    void read_doc(xmlDocPtr doc, XMLSerializerFactory& fact) throw(SerializeError);
+    void read_doc(xmlDocPtr doc, XMLSerializerFactory& fact) throw(SerializerError);
     
     /**
       \brief Restore all the resources from the passed xml node
diff --git a/plugins/xmlsave/src/xml_serializer_factory.cc b/plugins/xmlsave/src/xml_serializer_factory.cc
index 06aec14..1a0ed3a 100644
--- a/plugins/xmlsave/src/xml_serializer_factory.cc
+++ b/plugins/xmlsave/src/xml_serializer_factory.cc
@@ -25,7 +25,6 @@
 #include "history.hh"
 #include "resource.hh"
 // #include "backend/process.hh"
-#include "backend/serializer_error.hh"
 
 using namespace sgpem;
 
@@ -50,7 +49,7 @@ History* XMLSerializerFactory::get_history()
 }
 
 void
-XMLSerializerFactory::factory_method(const Glib::ustring& class_name, Parameters& parameters) throw(SerializeError)
+XMLSerializerFactory::factory_method(const Glib::ustring& class_name, Parameters& parameters) throw(SerializerError)
 {
   if(class_name == "Resource")
   {
@@ -241,7 +240,7 @@ XMLSerializerFactory::create_subrequest(Parameters& parameters)
 
     int old_key=0;
     int lasts_for=0;
-    int places=1;
+    //int places=1;
     Parameters::iterator pos;
     resource_key_t new_key = 0;
     
@@ -260,10 +259,10 @@ XMLSerializerFactory::create_subrequest(Parameters& parameters)
     }
     
     // read "priority" property
-    pos = parameters.find(Glib::ustring("how-many"));
-    if (pos != parameters.end()) {
-      string_to_int(pos->second, places);
-    }
+    //pos = parameters.find(Glib::ustring("how-many"));
+    //if (pos != parameters.end()) {
+    //  string_to_int(pos->second, places);
+    //}
 
     // read "priority" property
     pos = parameters.find(Glib::ustring("lasts-for"));
@@ -271,7 +270,8 @@ XMLSerializerFactory::create_subrequest(Parameters& parameters)
       string_to_int(pos->second, lasts_for);
     }
 
-    return _hist->add_subrequest(*_last_request, new_key, (History::time_t)lasts_for, (History::size_t)places);
+    //FIXME places?
+    return _hist->add_subrequest(*_last_request, new_key, (History::time_t)lasts_for/*, (History::size_t)places*/);
   }
   // add a sub request - Request, resource_key, duration, places
 }
diff --git a/plugins/xmlsave/src/xml_serializer_factory.hh b/plugins/xmlsave/src/xml_serializer_factory.hh
index 5935eb0..b0fa3a0 100644
--- a/plugins/xmlsave/src/xml_serializer_factory.hh
+++ b/plugins/xmlsave/src/xml_serializer_factory.hh
@@ -24,6 +24,7 @@
 #include "config.h"
 #include "history.hh"
 #include "environment.hh"
+#include "serializer_error.hh"
 
 #include <glibmm/ustring.h>
 #include <map>
@@ -76,7 +77,7 @@ namespace sgpem
       
       \throw SerializerError If not all necessary parameters for an object creation are provided
      */
-    void factory_method(const Glib::ustring& class_name, Parameters& parameters) throw(SerializeError);
+    void factory_method(const Glib::ustring& class_name, Parameters& parameters) throw(SerializerError);
   protected:
   private:
     typedef Environment::resource_key_t      resource_key_t;
diff --git a/plugins/xmlsave/src/xml_visitor.cc b/plugins/xmlsave/src/xml_visitor.cc
index 9eecf82..eb55add 100644
--- a/plugins/xmlsave/src/xml_visitor.cc
+++ b/plugins/xmlsave/src/xml_visitor.cc
@@ -300,15 +300,16 @@ void XMLVisitor::from_subrequest(xmlNodePtr parent, const SubRequest& obj) throw
   {
 
     Glib::ustring strResource;
-    Glib::ustring strHowMany;
+    //Glib::ustring strHowMany;
     Glib::ustring strLastsFor;
     int_to_string(obj.get_resource_key(), strResource);
-    int_to_string(obj.get_places(), strHowMany);
+    //FIXME places?
+    //int_to_string(obj.get_places(), strHowMany);
     int_to_string(obj.get_length(), strLastsFor);
 
     xmlNodePtr subrequest_node = xmlNewChild(parent, NULL, (const xmlChar *) "subrequest", NULL);
     xmlNewProp(subrequest_node, (const xmlChar *) "resource", (const xmlChar *) strResource.c_str());
-    xmlNewProp(subrequest_node, (const xmlChar *) "how-many", (const xmlChar *) strHowMany.c_str());
+    //xmlNewProp(subrequest_node, (const xmlChar *) "how-many", (const xmlChar *) strHowMany.c_str());
     xmlNewProp(subrequest_node, (const xmlChar *) "lasts-for", (const xmlChar *) strLastsFor.c_str());
   }
   else
diff --git a/src/backend/dynamic_process.cc b/src/backend/dynamic_process.cc
index 98e83a3..869cbce 100644
--- a/src/backend/dynamic_process.cc
+++ b/src/backend/dynamic_process.cc
@@ -122,6 +122,10 @@ DynamicProcess::get_state() const
     if (future > 0) // running == 0 && ready == 0 && blocked == 0 && terminated == 0
       return state_future;
 
+    // I'm not sure if we can get here (maybe if there are no threads?),
+    // but I don't like this compiler warning: 'control reaches end of non-void function'
+    return state_future;
+    
 	// Since premature optimization is the root of all evil, and the
 	// following code was very fast but also very wrong, the coder
 	// will be punished by allowing her to code in C++ just after
diff --git a/src/backend/serializer.cc b/src/backend/serializer.cc
index 2f61cc4..82037b3 100644
--- a/src/backend/serializer.cc
+++ b/src/backend/serializer.cc
@@ -22,6 +22,11 @@
 
 using namespace sgpem;
 
+Serializer::Serializer()
+{
+  SerializersGatekeeper::get_instance().register_serializer(this);
+}    
+
 Serializer::~Serializer()
 {}
 
diff --git a/src/backend/serializer.hh b/src/backend/serializer.hh
index b08faba..be97132 100644
--- a/src/backend/serializer.hh
+++ b/src/backend/serializer.hh
@@ -23,6 +23,7 @@
 
 #include "config.h"
 #include "history.hh"
+#include "serializer_error.hh"
 
 #include <glibmm/ustring.h>
 
@@ -33,10 +34,11 @@ namespace sgpem
   class Serializer
   {
   public:
+    Serializer();  
     virtual ~Serializer() = 0;
 
-    virtual void save_snapshot(const Glib::ustring& filename, const History& hist) throw(SerializeError) = 0;
-    virtual void restore_snapshot(const Glib::ustring& filename, History& hist) throw(SerializeError) = 0;
+    virtual void save_snapshot(const Glib::ustring& filename, const History& hist) throw(SerializerError) = 0;
+    virtual void restore_snapshot(const Glib::ustring& filename, History& hist) throw(SerializerError) = 0;
     virtual const Glib::ustring get_filename_extension() = 0;
     virtual const Glib::ustring get_filename_description() = 0;
   protected:
diff --git a/src/testsuite/test-history.cc b/src/testsuite/test-history.cc
index daf925a..5bbe74a 100644
--- a/src/testsuite/test-history.cc
+++ b/src/testsuite/test-history.cc
@@ -419,7 +419,7 @@ main(int argc, char** argv)
   }
   test << endl;
 
-  ThreadCreationData p1_3_d = { "p1_3", &p1, 3, 4 };
+  ThreadCreationData p1_3_d = { "p1_3", &p1, 3, 4, 0 };
   
   Thread& p1_3 = h.add_thread(p1_3_d.name,
                               *p1_3_d.parent,
diff --git a/src/text_simulation.cc b/src/text_simulation.cc
index f526100..1f52c6f 100644
--- a/src/text_simulation.cc
+++ b/src/text_simulation.cc
@@ -23,6 +23,8 @@
 #include "backend/cpu_policy_manager.hh"
 #include "backend/policy_parameters.hh"
 #include "backend/history.hh"
+#include "backend/serializers_gatekeeper.hh"
+#include "backend/serializer.hh"
 #include "backend/static_process.hh"
 #include "backend/static_resource.hh"
 #include "backend/static_thread.hh"
@@ -1288,6 +1290,37 @@ TextSimulation::on_remove_subrequest(const Tokens& arguments)
   h.remove(*r);
 }
 
+void 
+TextSimulation::on_save(const Tokens& arguments)
+{
+  if(!check_arguments_num(arguments, 1))
+    return;
+
+  ustring filename = arguments[0];
+
+  try
+  {
+    vector<Serializer*> serializers = 
+      SerializersGatekeeper::get_instance().get_registered();
+
+    Serializer& serializer = *serializers.at(0);
+
+    const History& history = Simulation::get_instance().get_history();
+    
+    serializer.save_snapshot(filename, history);
+  }
+  catch(out_of_range e)
+  {
+    p_stderr(_("ERROR: No registered serializer available\n"));
+  }
+  catch(SerializerError e)
+  {
+    string msg = _("ERROR: ");
+  
+    p_stderr(msg + e.what() + "\n");
+  }
+}
+
 void
 TextSimulation::p_stdout(const ustring& str)
 {
@@ -1327,6 +1360,7 @@ TextSimulation::parse_command(TextSimulation& sim, const ustring& str)
   command_handlers["SHOW"] = &TextSimulation::on_show;
   command_handlers["ADD"] = &TextSimulation::on_add;
   command_handlers["REMOVE"] = &TextSimulation::on_remove;
+  command_handlers["SAVE"] = &TextSimulation::on_save;
   command_handlers["QUIT"] = &TextSimulation::on_quit;
     
   Tokens arguments = tokenize(str);
diff --git a/src/text_simulation.hh b/src/text_simulation.hh
index e6141a9..9730592 100644
--- a/src/text_simulation.hh
+++ b/src/text_simulation.hh
@@ -106,6 +106,7 @@ namespace sgpem
     void on_remove_thread(const Tokens& arguments);
     void on_remove_request(const Tokens& arguments);
     void on_remove_subrequest(const Tokens& arguments);
+    void on_save(const Tokens& arguments);
     
     // FIXME This is a temporary replacement for the 
     // to-be written I/O layer