diff --git a/plugins/xmlsave/src/testsuite/test-xml_visitor.cc b/plugins/xmlsave/src/testsuite/test-xml_visitor.cc
new file mode 100644
index 0000000..4a6cc9a
--- /dev/null
+++ b/plugins/xmlsave/src/testsuite/test-xml_visitor.cc
@@ -0,0 +1,132 @@
+// src/testsuite/test-history.cc - Copyright 2005, 2006, University
+//               of Padova, dept. of Pure and Applied
+//               Mathematics
+//
+// This file is part of SGPEMv2.
+//
+// This is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// SGPEMv2 is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with SGPEMv2; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+
+/* This executable tests for workingness of the whole History services,
+ * and nothing else. */
+
+#include "config.h"
+#include "gettext.h"
+
+#include <glibmm/ustring.h>
+
+#include <cassert>
+#include <iostream>
+
+#include "backend/concrete_environment.hh"
+#include "backend/concrete_history.hh"
+#include "backend/history_observer.hh"
+#include "xml_serializer.hh"
+
+using namespace sgpem;
+using namespace std;
+
+
+void fillHistory(History &hist)
+{
+  cout << "filling history..." << endl << endl;
+  // add a resource - name, preemptable, places, availability
+  History::ResourcePair respair = hist.add_resource(Glib::ustring("Resource 1"), false, 1, 2);
+  // and print his values
+  cout << "resource name: " << respair.second->get_name() << " key: " << respair.first << " places: " << respair.second->get_places() << endl;
+
+  // add a process - name, arrival time, priority
+  Process&   p1 =  hist.add_process(Glib::ustring("Process 1"), 5, 2); // name, arrival time, priority
+  // and print his values
+  cout << "process name: " << p1.get_name() << " arrival_time: " << p1.get_arrival_time() << " base_priority: " << p1.get_base_priority() << endl;
+
+  // add a process - name, arrival time, priority
+  Process&   p2 =  hist.add_process(Glib::ustring("Process 2"), 7, 3); // name, arrival time, priority
+  // and print his values
+  cout << "process name: " << p2.get_name() << " arrival_time: " << p2.get_arrival_time() << " base_priority: " << p2.get_base_priority() << endl;
+
+  // add a process - name, arrival time, priority
+  Process&   p3 =  hist.add_process(Glib::ustring("Process 3"), 9, 1); // name, arrival time, priority
+  // and print his values
+  cout << "process name: " << p3.get_name() << " arrival_time: " << p3.get_arrival_time() << " base_priority: " << p3.get_base_priority() << endl;
+
+  // add a thread - name, parent, cpu time, arrival time, priority
+  Thread&   p1_t1 =  hist.add_thread(Glib::ustring("Process 1 - Thread 1"), p1, 3, 2, 6);
+  // and print his values
+  cout << "thread name: " << p1_t1.get_name() << " total_cpu_time: " << p1_t1.get_total_cpu_time() << " arrival_time: " << p1_t1.get_arrival_time() << " base_priority: " << p1_t1.get_base_priority() << endl;
+
+  // add a request - Thread, time
+  Request&   req1 =  hist.add_request(p1_t1, 7);
+  // and print his values
+  cout << "request arrival_time: " << req1.get_instant() << endl;
+
+  // add a sub request - Request, resource_key, duration, places
+  SubRequest& req1_sub1 = hist.add_subrequest(req1, respair.first, 5, 2);
+  // and print his values
+  cout << "sub request resource_key: " << req1_sub1.get_resource_key() << " places: " << req1_sub1.get_places() << " length: " << req1_sub1.get_length() << endl;
+  cout << endl;
+}
+
+
+void dumpEnvironment(const Environment& env)
+{
+  const Environment::Processes& pvect = env.get_processes();
+  typedef std::vector<Process*>::const_iterator proc_iterator;
+
+  proc_iterator iter = pvect.begin();
+  proc_iterator end = pvect.end();
+  while(iter!=end)
+  {
+    Process* p = (*iter);
+    cout << "process name: " << p->get_name() << " arrival_time: " << p->get_arrival_time() << " base_priority: " << p->get_base_priority() << endl;
+    iter++;
+  
+
+    typedef std::vector<Thread*> Threads;
+    typedef std::vector<Thread*>::const_iterator thr_iterator;
+    const Threads& tvect = p->get_threads();
+    thr_iterator iter1 = tvect.begin();
+    thr_iterator end1  = tvect.end();
+    while(iter1!=end1)
+    {
+      
+      Thread* p = (*iter1);
+      cout << "Thread name: " << p->get_name() << " arrival_time: " << p->get_arrival_time() << " base_priority: " << p->get_base_priority() << endl;
+      iter1++;
+    }
+
+
+  }
+}
+
+
+int
+main(int argc, char** argv)
+{
+//  using namespace sgpem;
+
+  ConcreteHistory hist;
+
+  fillHistory(hist);
+
+  const Environment& env = hist.get_last_environment();
+  dumpEnvironment(env);
+
+  XMLSerializer xmlser;
+  xmlser.save_snapshot(Glib::ustring("xml-visit.xml"), hist);
+
+
+  // typedef std::vector<Process*>    Processes;
+	return 0;
+}
diff --git a/plugins/xmlsave/src/xml_serializer.cc b/plugins/xmlsave/src/xml_serializer.cc
new file mode 100644
index 0000000..0bef0e6
--- /dev/null
+++ b/plugins/xmlsave/src/xml_serializer.cc
@@ -0,0 +1,148 @@
+// src/backend/serialize_visitor.cc - Copyright 2005, 2006, University
+//               of Padova, dept. of Pure and Applied
+//               Mathematics
+//
+// This file is part of SGPEMv2.
+//
+// This is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// SGPEMv2 is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with SGPEMv2; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+
+#include "xml_serializer.hh"
+#include "xml_visitor.hh"
+
+#include "backend/string_utils.hh"
+#include "backend/environment.hh"
+#include "backend/history.hh"
+#include "backend/concrete_environment.hh"
+#include "backend/concrete_history.hh"
+#include "backend/process.hh"
+#include "backend/serializer_error.hh"
+
+using namespace sgpem;
+
+XMLSerializer::~XMLSerializer()
+{
+}
+
+XMLSerializer::XMLSerializer()
+{
+}
+
+
+
+void XMLSerializer::save_snapshot(const Glib::ustring& filename, const History& hist)
+{
+  /* COMPAT: Do not genrate nodes for formatting spaces */
+  LIBXML_TEST_VERSION
+  xmlKeepBlanksDefault(0);
+  
+  xmlDocPtr doc;
+  doc = xmlNewDoc((const xmlChar *)"1.0");
+  if(doc!=NULL){
+    fill_doc(doc, hist);
+    int nwritten = xmlSaveFormatFile (filename.c_str(), doc, 1);
+    if(nwritten<0)
+    {
+      throw SerializerError("Error writing xml doc to output stream.");
+    }
+  }
+  else
+  {
+    throw SerializerError("Internal Error creating xml doc.");
+  }
+  
+  /* Clean up everything else before quitting. */
+  xmlCleanupParser();
+}
+
+void XMLSerializer::restore_snapshot(const Glib::ustring& filename, History& hist)
+{
+    // TODO - all to do!!
+    // DEBUG - remove me when finished
+}
+
+
+const Glib::ustring XMLSerializer::get_filename_extension()
+{
+    return Glib::ustring("ocio");
+}
+
+
+const Glib::ustring XMLSerializer::get_filename_description()
+{
+    return Glib::ustring("SGPEMv2 XML formatted snapshot save file");
+}
+
+void XMLSerializer::fill_doc(xmlDocPtr doc, const History& hist)
+{
+    xmlNodePtr root_node = NULL;/* node pointers */
+    /*
+     * Creates a new document, a node and set it as a root node
+     */
+    root_node = xmlNewNode(NULL, (const xmlChar *) "sgpem");
+    xmlDocSetRootElement(doc, root_node);
+
+    /*
+     * Creates a DTD declaration. Isn't mandatory. 
+     */
+    // dtd = xmlCreateIntSubset(doc, BAD_CAST "root", NULL, BAD_CAST "tree2.dtd");
+
+    /* 
+     * xmlNewChild() creates a new node, which is "attached" as child node
+     * of root_node node. 
+     */
+    xmlNodePtr resources_node = xmlNewChild(root_node, NULL, (const xmlChar *) "resources", NULL);
+    /* 
+     * The same as above, but the new child node doesn't have a content 
+     */
+    xmlNodePtr schedulables_node = xmlNewChild(root_node, NULL, (const xmlChar *) "schedulables", NULL);
+
+    fill_resources(resources_node, hist);
+    fill_schedulables(schedulables_node, hist);
+}
+
+void XMLSerializer::fill_resources(xmlNodePtr resources, const History& hist)
+{
+}
+
+void XMLSerializer::fill_schedulables(xmlNodePtr schedulables, const History& hist)
+{
+    
+
+    const Environment& env = hist.get_last_environment();
+
+    const Environment::Processes& pvect = env.get_processes();
+    typedef std::vector<Process*>::const_iterator proc_iterator;
+  
+    proc_iterator iter = pvect.begin();
+    proc_iterator end = pvect.end();
+    while(iter!=end)
+    {
+      XMLVisitor xvisit(schedulables);
+      xvisit.from_process(*(*iter));
+      /*
+      Glib::ustring strPriority;
+      Glib::ustring strArrivalTime;
+      Process* p = (*iter);
+      int_to_string(p->get_base_priority(), strPriority);
+      int_to_string(p->get_arrival_time(), strArrivalTime);
+
+      xmlNodePtr process_node = xmlNewChild(schedulables, NULL, (const xmlChar *) p->get_name().c_str(), NULL);
+      xmlNewProp(process_node, (const xmlChar *) "name", (const xmlChar *) p->get_name().c_str());
+      xmlNewProp(process_node, (const xmlChar *) "priority", (const xmlChar *) strPriority.c_str());
+      xmlNewProp(process_node, (const xmlChar *) "arrival-time", (const xmlChar *) strArrivalTime.c_str());
+      */
+      iter++;
+    }
+}
diff --git a/plugins/xmlsave/src/xml_serializer.hh b/plugins/xmlsave/src/xml_serializer.hh
new file mode 100644
index 0000000..4f1a3a2
--- /dev/null
+++ b/plugins/xmlsave/src/xml_serializer.hh
@@ -0,0 +1,53 @@
+// src/backend/serializer.hh - Copyright 2005, 2006, University
+//               of Padova, dept. of Pure and Applied
+//               Mathematics
+//
+// This file is part of SGPEMv2.
+//
+// This is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// SGPEMv2 is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with SGPEMv2; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+
+#ifndef XML_SERIALIZER_HH
+#define XML_SERIALIZER_HH 1
+
+#include "config.h"
+#include "backend/serializer.hh"
+
+#include <glibmm/ustring.h>
+#include <libxml/xmlmemory.h>
+#include <libxml/parser.h>
+
+namespace sgpem
+{
+  class XMLSerializer;
+
+  class XMLSerializer : public Serializer
+  {
+  public:
+    XMLSerializer();
+    virtual ~XMLSerializer();
+
+    virtual void save_snapshot(const Glib::ustring& filename, const History& hist);
+    virtual void restore_snapshot(const Glib::ustring& filename, History& hist);
+    virtual const Glib::ustring get_filename_extension();
+    virtual const Glib::ustring get_filename_description();
+  protected:
+  private:
+    void fill_doc(xmlDocPtr doc, const History& hist);
+    void fill_resources(xmlNodePtr doc, const History& hist);
+    void fill_schedulables(xmlNodePtr doc, const History& hist);
+  };
+}
+
+#endif
diff --git a/plugins/xmlsave/src/xml_visitor.cc b/plugins/xmlsave/src/xml_visitor.cc
new file mode 100644
index 0000000..a0576e7
--- /dev/null
+++ b/plugins/xmlsave/src/xml_visitor.cc
@@ -0,0 +1,150 @@
+// src/backend/serialize_visitor.cc - Copyright 2005, 2006, University
+//               of Padova, dept. of Pure and Applied
+//               Mathematics
+//
+// This file is part of SGPEMv2.
+//
+// This is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// SGPEMv2 is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with SGPEMv2; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+
+#include "xml_visitor.hh"
+
+#include "backend/string_utils.hh"
+#include "backend/resource.hh"
+#include "backend/process.hh"
+#include "backend/thread.hh"
+#include "backend/request.hh"
+#include "backend/sub_request.hh"
+#include "backend/serializer_error.hh"
+
+
+using namespace sgpem;
+
+/*
+#include <iostream>
+using namespace std;
+*/
+
+
+XMLVisitor::XMLVisitor(xmlNodePtr current)
+  : _current(current)
+{
+}
+
+XMLVisitor::~XMLVisitor()
+{
+}
+
+void XMLVisitor::from_resource(const Resource& obj)
+{
+}
+
+
+void XMLVisitor::from_process(const Process& obj)
+{
+  from_process(_current, obj);
+}
+
+
+void XMLVisitor::from_thread(const Thread& obj)
+{
+  from_thread(_current, obj);
+}
+
+
+void XMLVisitor::from_request(const Request& obj)
+{
+}
+
+
+void XMLVisitor::from_subrequest(const SubRequest& obj)
+{
+}
+
+
+
+void XMLVisitor::from_resource(xmlNodePtr parent, const Resource& obj)
+{
+}
+
+
+void XMLVisitor::from_process(xmlNodePtr parent, const Process& obj)
+{
+  if(parent!=NULL)
+  {
+    Glib::ustring strPriority;
+    Glib::ustring strArrivalTime;
+    int_to_string(obj.get_base_priority(), strPriority);
+    int_to_string(obj.get_arrival_time(), strArrivalTime);
+
+    xmlNodePtr process_node = xmlNewChild(parent, NULL, (const xmlChar *) "process", NULL);
+    xmlNewProp(process_node, (const xmlChar *) "name", (const xmlChar *) obj.get_name().c_str());
+    xmlNewProp(process_node, (const xmlChar *) "priority", (const xmlChar *) strPriority.c_str());
+    xmlNewProp(process_node, (const xmlChar *) "arrival-time", (const xmlChar *) strArrivalTime.c_str());
+
+    // make a threads subnode
+    xmlNodePtr threads_node = xmlNewChild(process_node, NULL, (const xmlChar *) "threads", NULL);
+
+    // iterate on threads
+    typedef std::vector<Thread*> Threads;
+    typedef std::vector<Thread*>::const_iterator thr_iterator;
+    const Threads& tvect = ((Process&)obj).get_threads();
+    thr_iterator iter = tvect.begin();
+    thr_iterator end  = tvect.end();
+    while(iter!=end)
+    {
+      from_thread(threads_node, *(*iter));
+      iter++;
+    }
+  }
+  else
+  {
+    throw SerializerError("Error trying to add process to empty XML node.");
+  }
+}
+
+
+void XMLVisitor::from_thread(xmlNodePtr parent, const Thread& obj)
+{
+  if(parent!=NULL)
+  {
+
+    Glib::ustring strPriority;
+    Glib::ustring strArrivalTime;
+    Glib::ustring strLastsTime;
+    int_to_string(obj.get_base_priority(), strPriority);
+    int_to_string(obj.get_arrival_time(), strArrivalTime);
+    int_to_string(obj.get_elapsed_time(), strLastsTime);
+    // get_elapsed_time() or get_total_cpu_time() ???
+    xmlNodePtr thread_node = xmlNewChild(_current, NULL, (const xmlChar *) "thread", NULL);
+    xmlNewProp(thread_node, (const xmlChar *) "name", (const xmlChar *) obj.get_name().c_str());
+    xmlNewProp(thread_node, (const xmlChar *) "priority", (const xmlChar *) strPriority.c_str());
+    xmlNewProp(thread_node, (const xmlChar *) "arrival-delta", (const xmlChar *) strArrivalTime.c_str());
+    xmlNewProp(thread_node, (const xmlChar *) "lasts-for", (const xmlChar *) strLastsTime.c_str());
+  }
+  else
+  {
+    throw SerializerError("Error trying to add thread to empty XML node.");
+  }
+}
+
+
+void XMLVisitor::from_request(xmlNodePtr parent, const Request& obj)
+{
+}
+
+
+void XMLVisitor::from_subrequest(xmlNodePtr parent, const SubRequest& obj)
+{
+}
diff --git a/plugins/xmlsave/src/xml_visitor.hh b/plugins/xmlsave/src/xml_visitor.hh
new file mode 100644
index 0000000..c20e2e1
--- /dev/null
+++ b/plugins/xmlsave/src/xml_visitor.hh
@@ -0,0 +1,67 @@
+// src/backend/serialize_visitor.hh - Copyright 2005, 2006, University
+//               of Padova, dept. of Pure and Applied
+//               Mathematics
+//
+// This file is part of SGPEMv2.
+//
+// This is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 2 of the License, or
+// (at your option) any later version.
+//
+// SGPEMv2 is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with SGPEMv2; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+
+#ifndef XML_VISITOR_HH
+#define XML_VISITOR_HH 1
+
+namespace sgpem
+{
+  class Resource;
+  class Process;
+  class Thread;
+  class Request;
+  class SubRequest;
+}
+
+#include "config.h"
+#include "backend/serializer_visitor.hh"
+
+#include <glibmm/ustring.h>
+#include <libxml/xmlmemory.h>
+#include <libxml/parser.h>
+
+namespace sgpem
+{
+  class XMLVisitor;
+
+  class XMLVisitor : public SerializerVisitor
+  {
+  public:
+    XMLVisitor(xmlNodePtr current);
+    virtual ~XMLVisitor();
+
+    virtual void from_resource(const Resource& obj);
+    virtual void from_process(const Process& obj);
+    virtual void from_thread(const Thread& obj);
+    virtual void from_request(const Request& obj);
+    virtual void from_subrequest(const SubRequest& obj);
+  private:
+    void from_resource(xmlNodePtr parent, const Resource& obj);
+    void from_process(xmlNodePtr parent, const Process& obj);
+    void from_thread(xmlNodePtr parent, const Thread& obj);
+    void from_request(xmlNodePtr parent, const Request& obj);
+    void from_subrequest(xmlNodePtr parent, const SubRequest& obj);
+    
+    xmlNodePtr _current;
+  };
+}
+
+#endif
+