diff --git a/include/application.php b/include/application.php
index 256afa1..c412014 100644
--- a/include/application.php
+++ b/include/application.php
@@ -13,6 +13,9 @@ require_once(BASE."include/maintainer.php");
 require_once(BASE."include/tableve.php");
 require_once(BASE."include/db_filter_ui.php");
 
+// Added by Natalia Portillo for QEMU support.
+require_once(BASE."include/qemusystem.php");
+
 define("PLATINUM_RATING", "Platinum");
 define("GOLD_RATING", "Gold");
 define("SILVER_RATING", "Silver");
diff --git a/include/qemusystem.php b/include/qemusystem.php
new file mode 100644
index 0000000..ca831b7
--- /dev/null
+++ b/include/qemusystem.php
@@ -0,0 +1,576 @@
+<?php
+/***************************************************/
+/* this class represents a category + its children */
+/***************************************************/
+
+/**
+ * Category class for handling categories.
+ */
+class qemuSystem {
+    var $iSysId;
+    var $iParentId;
+    var $sName;
+    var $sDescription;
+    var $aApplicationsIds;  // an array that contains the appId of every application linked to this category
+    var $aSubcatsIds;        // an array that contains the appId of every application linked to this category
+
+
+    /**    
+     * constructor, fetches the data.
+     */
+    function qemuSystem($iSysId = null)
+    {
+        // we are working on an existing category
+        if($iSysId=="0" || $iSysId)
+        {
+            /*
+             * We fetch the data related to this vendor.
+             */
+            $sQuery = "SELECT *
+                       FROM qemuSystems
+                       WHERE qsysId = '?' ORDER BY qsysName;";
+            if($hResult = query_parameters($sQuery, $iSysId))
+            {
+                $oRow = query_fetch_object($hResult);
+                if($oRow)
+                {
+                    $this->iSysId = $iSysId;
+                    $this->iParentId = $oRow->qsysParent;
+                    $this->sName = $oRow->qsysName;
+                    $this->sDescription = $oRow->qsysDescription;
+                }
+            }
+
+            /*
+             * We fetch applicationsIds. 
+             */
+            $sQuery = "SELECT qsysId
+                       FROM appFamily
+                       WHERE qsysId = '?'
+                       AND state = 'accepted' ORDER BY appName";
+            if($hResult = query_parameters($sQuery, $iSysId))
+            {
+                while($oRow = query_fetch_object($hResult))
+                {
+                    $this->aApplicationsIds[] = $oRow->appId;
+                }
+            }
+
+            /*
+             * We fetch subqsysIds. 
+             */
+            $sQuery = "SELECT qsysId
+                       FROM qemuSystems
+                       WHERE qsysParent = '?' ORDER BY qsysName;";
+            if($hResult = query_parameters($sQuery, $iSysId))
+            {
+                while($oRow = query_fetch_object($hResult))
+                {
+                    $this->aSubcatsIds[] = $oRow->qsysId;
+                }
+            }
+        }
+    }
+
+
+    /**
+     * Creates a new category.
+     */
+    function create()
+    {
+        $hResult = query_parameters("INSERT INTO qemuSystems (qsysName, qsysDescription, qsysParent) ".
+                                    "VALUES('?', '?', '?')",
+                                    $this->sName, $this->sDescription, $this->iParentId);
+        if($hResult)
+        {
+            $this->iSysId = query_appdb_insert_id();
+            $this->qemuSystem($this->iSysId);
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * Update category.
+     * Returns true on success and false on failure.
+     */
+    function update()
+    {
+        if(!query_parameters("UPDATE qemuSystems SET qsysName = '?', qsysDescription = '?', qsysParent = '?' WHERE qsysId = '?'",
+                             $this->sName, $this->sDescription, $this->iParentId, $this->iSysId))
+            return false;
+
+        return true;
+    }
+
+
+    /**    
+     * Deletes the category from the database. 
+     */
+    function delete()
+    {
+        if(!$this->canEdit())
+            return false;
+
+        if(sizeof($this->aApplicationsIds)>0)
+            return FALSE;
+
+        $sQuery = "DELETE FROM qemuSystems 
+                    WHERE qsysId = '?' 
+                    LIMIT 1";
+        query_parameters($sQuery, $this->iSysId);
+
+        return true;
+    }
+
+    function objectGetMailOptions($sAction, $bMailSubmitter, $bParentAction)
+    {
+        return new mailOptions();
+    }
+
+    function objectGetChildren()
+    {
+        /* We don't have any (or we do, sort of, but we don't use them for anything at the moment) */
+                return array();
+    }
+
+    /* Get a category's subcategory objects.  Names are indented according
+       to subcategory level */
+    function getSubCatList($iLevel = 0)
+    {
+        $aOut = array();
+        $iId = $this->iSysId ? $this->iSysId : 0;
+
+        $sIndent = '';
+        for($i = 0; $i < $iLevel; $i++)
+            $sIndent .= '&nbsp; &nbsp;';
+
+        $hResult = query_parameters("SELECT * FROM qemuSystems WHERE qsysParent = '?'
+                                     ORDER BY qsysName", $iId);
+
+        while($oRow = mysql_fetch_object($hResult))
+        {
+            $oCat = new qemuSystem($oRow->qsysId);
+            $oCat->sName = $sIndent.$oCat->sName;
+            $aOut[] = $oCat;
+            $aOut = array_merge($aOut, $oCat->getSubCatList($iLevel + 1));
+        }
+        return $aOut;
+    }
+
+    /* Get all category objects, ordered and with category names indented
+       according to subcategory level.
+       Optionally includes the 'Main' top category. */
+    static function getOrderedList($bIncludeMain = false)
+    {
+        $oCat = new qemuSystem();
+
+        if(!$bIncludeMain)
+            return $oCat->getSubCatList(0);
+
+        $oCat->sName = 'Main';
+        $aCats = array($oCat);
+        $aCats = array_merge($aCats, $oCat->getSubCatList(1));
+
+        return $aCats;
+    }
+
+    /* Returns an SQL statement that will match items in the current category
+       and all sub-categories */
+    public function getSqlQueryPart()
+    {
+        $sRet = '';
+        $aSubCats = $this->getSubCatList();
+        $sRet .= " ( qsysId = '{$this->iSysId}' ";
+        foreach($aSubCats as $oCat)
+        {
+            $iSysId = $oCat->objectGetId();
+            $sRet .= " OR qsysId = '$iSysId' ";
+        }
+        $sRet .= ") ";
+
+        return $sRet;
+    }
+
+    function objectGetMail($sAction, $bMailSubmitter, $bParentAction)
+    {
+        /* We don't send notification mails */
+                return array(null, null, null);
+    }
+
+    /**
+     * returns a path like:
+     *
+     *     { ROOT, Games, Simulation }
+     */
+    function getCategoryPath()
+    {
+        $aPath = array();
+        $iSysId  = $this->iSysId;
+
+        /* loop, working up through categories until we have no parent */
+        while($iSysId != 0)
+        {
+            $hResult = query_parameters("SELECT qsysName, qsysId, qsysParent FROM qemuSystems WHERE qsysId = '?'",
+                                       $iSysId);
+            if(!$hResult || query_num_rows($hResult) != 1)
+                break;
+            $oCatRow = query_fetch_object($hResult);
+            $aPath[] = array($oCatRow->qsysId, $oCatRow->qsysName);
+            $iSysId = $oCatRow->qsysParent;
+        }
+        $aPath[] = array(0, "ROOT");
+        return array_reverse($aPath);
+    }
+
+    /* return the total number of applications in this category */
+    function getApplicationCount($depth = null)
+    {
+        $MAX_DEPTH = 5;
+
+        if($depth)
+            $depth++;
+        else
+            $depth = 0;
+
+        /* if we've reached our max depth, just return 0 and stop recursing */
+        if($depth >= $MAX_DEPTH)
+            return 0;
+
+        $totalApps = 0;
+
+        /* add on all apps in each category this category includes */
+        if($this->aSubcatsIds)
+        {
+            while(list($i, $iSubqsysId) = each($this->aSubcatsIds))
+            {
+                $subCat = new qemuSystem($iSubqsysId);
+                $totalApps += $subCat->getApplicationCount($depth);
+            }
+        }
+
+        $totalApps += sizeof($this->aApplicationsIds); /* add on the apps at this category level */
+        
+        return $totalApps;
+    }
+
+    /**
+     * create the Category: line at the top of appdb pages$
+     */
+    function make_cat_path($aPath, $iAppId = '', $iVersionId = '')
+    {
+        $sStr = "";
+        $iCatCount = 0;
+        while(list($iSysIdx, list($iSysId, $sName)) = each($aPath))
+        {
+            if($sName == "ROOT")
+                $sqsysName = "Main";
+            else
+                $sqsysName = $sName;
+
+            if ($iCatCount > 0) $sStr .= " &gt; ";
+            $sStr .= html_ahref($sqsysName,"objectManager.php?sClass=qemuSystem&iId=$iSysId&sAction=view&sTitle=Browse+OSes");
+            $iCatCount++;
+        }
+
+        if($iAppId)
+        {
+            $oApp = new Application($iAppId);
+            if($iVersionId)
+            {
+                $oVersion = new Version($iVersionId);
+                $sStr .= " &gt; ".$oApp->objectMakeLink();
+                $sStr .= " &gt; ".$oVersion->sName;
+            } else
+            {
+                $sStr .= " &gt; ".$oApp->sName;
+            }
+        }
+
+        return $sStr;
+    }
+
+    public function objectGetState()
+    {
+        // We currenly don't queue categories
+        return 'accepted';
+    }
+
+    function objectGetId()
+    {
+        return $this->iSysId;
+    }
+
+    public function objectMakeLink()
+    {
+        return '<a href="'.$this->objectMakeUrl()."\">{$this->sName}</a>'";
+    }
+
+    public function objectMakeUrl()
+    {
+        return BASE."objectManager.php?sClass=qemuSystem&sAction=view&iId={$this->iSysId}&sTitle=Browse+OSes";
+    }
+
+    public function objectAllowNullId($sAction)
+    {
+        switch($sAction)
+        {
+            case 'view':
+                return true;
+
+            default:
+                return false;
+        }
+    }
+
+    function objectGetSubmitterId()
+    {
+        /* We don't log that */
+        return 0;
+    }
+
+    function objectGetCustomVars($sAction)
+    {
+        switch($sAction)
+        {
+            case 'add':
+                return array('iParentId');
+
+            default:
+                return null;
+        }
+    }
+
+    function outputEditor($aValues = null)
+    {
+        $aCategories = qemuSystem::getOrderedList(true);
+        $aqsysNames = array();
+        $aCatIds = array();
+
+        $iParentId = $this->iParentId;
+        if(!$iParentId && $aValues)
+            $iParentId = getInput('iParentId', $aValues);
+
+        foreach($aCategories as $oCategory)
+        {
+            $aqsysNames[] = $oCategory->sName;
+            $aCatIds[] = $oCategory->objectGetId();
+        }
+
+        echo "<table border=\"0\" width=\"100%\" cellspacing=\"0\" cellpadding=\"2\">
+                <tr>
+                <td width=\"15%\" class=\"box-label\"><b>System name</b></td>
+                <td class=\"box-body\">
+                <input type=\"text\" size=\"50\" name=\"sName\" value=\"".$this->sName."\"> 
+                </td>
+                </tr>
+                <tr>
+                <td width=\"15%\" class=\"box-label\"><b>Description</b></td>
+                <td class=\"box-body\">
+                <input type=\"text\" size=\"50\" name=\"sDescription\" value=\"".$this->sDescription."\"> 
+                </td>
+                </tr>
+                <tr>
+                <td width=\"15%\" class=\"box-label\"><b>Parent</b></td>
+                <td class=\"box-body\">
+                ".html_select("iParentId",$aCatIds,$iParentId, $aqsysNames)." 
+                </td>
+                </tr>
+                </table>";
+    }
+
+    function allowAnonymousSubmissions()
+    {
+        return FALSE;
+    }
+
+    function getOutputEditorValues($aClean)
+    {
+        $this->sName = $aClean['sName'];
+        $this->iParentId = $aClean['iParentId'];
+        $this->sDescription = $aClean['sDescription'];
+    }
+
+    function mustBeQueued()
+    {
+        return $_SESSION['current']->hasPriv('admin');
+    }
+
+    function canEdit()
+    {
+        return $_SESSION['current']->hasPriv('admin');
+    }
+
+    /**
+     * display the full path of the Category we are looking at
+     */
+    function displayPath($appId, $versionId = '')
+    {
+        $sCatFullPath = qemuSystem::make_cat_path($this->getCategoryPath(), $appId, $versionId);
+        echo html_frame_start("",'98%','',2);
+        echo "<p><b>System: ". $sCatFullPath ."</b><br>\n";
+        echo html_frame_end();
+    }
+
+    public function display()
+    {
+        // list sub categories
+        $sCatFullPath = qemuSystem::make_cat_path($this->getCategoryPath());
+        $aSubs = $this->aSubcatsIds;
+
+        echo "<div class='default_container'>\n";
+
+        // Allow editing categories
+        if($this->canEdit())
+        {
+            $oM = new objectManager('qemuSystem', '', $this->iSysId);
+            $oM->setReturnTo($this->objectMakeUrl());
+            echo "<p>\n";
+            echo '<a href="'.$oM->makeUrl('add', null, 'Add system')."&iParentId={$this->iSysId}\">Add</a>";;
+            if($this->iSysId) // We can't edit the 'Main' category
+            {
+                echo ' &nbsp; &nbsp; ';
+                echo '<a href="'.$oM->makeUrl('edit', $this->iSysId, 'Edit system').'">Edit</a>';
+                echo ' &nbsp; &nbsp; ';
+                echo '<a href="'.$oM->makeUrl('delete', $this->iSysId, 'Delete system').'">Delete</a>';
+            }
+            echo "</p>\n";
+        }
+
+        // Output sub-categories
+        if($aSubs)
+        {
+            echo html_frame_start("",'98%','',2);
+            echo "<p><b>System: ". $sCatFullPath ."</b><br>\n";
+            echo html_frame_end();
+
+            echo html_frame_start("","98%","",0);
+
+            $oTable = new Table();
+            $oTable->SetWidth("100%");
+            $oTable->SetBorder(0);
+            $oTable->SetCellPadding(3);
+            $oTable->SetCellSpacing(1);
+
+            $oTableRow = new TableRow();
+            $oTableRow->SetClass("color4");
+            $oTableRow->AddTextCell("Sub system");
+            $oTableRow->AddTextCell("Description");
+            $oTableRow->AddTextCell("No. OSes");
+            $oTable->SetHeader($oTableRow);
+            
+            while(list($i,$iSubqsysId) = each($aSubs))
+            {
+                $oSubCat= new qemuSystem($iSubqsysId);
+
+                //set row color
+                $sColor = ($i % 2) ? "color0" : "color1"; 
+
+                $oTableRowHighlight = GetStandardRowHighlight($i);
+
+                $sUrl = $oSubCat->objectMakeUrl();
+
+                $oTableRowClick = new TableRowClick($sUrl);
+                $oTableRowClick->SetHighlight($oTableRowHighlight);
+
+                //get number of apps in this sub-category
+                $iAppcount = $oSubCat->getApplicationCount();
+
+                //format desc
+                $sDesc = substr(stripslashes($oSubCat->sDescription),0,70);
+
+                //display row
+                $oTableRow = new TableRow();
+                $oTableRow->SetClass($sColor);
+                $oTableRow->SetRowClick($oTableRowClick);
+
+                $oTableCell = new TableCell($oSubCat->sName);
+                $oTableCell->SetCellLink($sUrl);
+                $oTableRow->AddCell($oTableCell);
+                $oTableRow->AddTextCell("$sDesc &nbsp;");
+                $oTableRow->AddTextCell("$iAppcount &nbsp;");
+
+                $oTable->AddRow($oTableRow);
+            }
+
+            // output the table
+            echo $oTable->GetString();
+
+            echo html_frame_end( count($aSubs) . ' categories');
+        }
+
+
+        // list applications in this category
+        $aApps = $this->aApplicationsIds;
+        if($aApps)
+        {
+            echo html_frame_start("",'98%','',2);
+            echo "<p><b>System: ". $sCatFullPath ."</b><br>\n";
+            echo html_frame_end();
+            
+            echo html_frame_start("","98%","",0);
+
+            $oTable = new Table();
+            $oTable->SetWidth("100%");
+            $oTable->SetBorder(0);
+            $oTable->SetCellPadding(3);
+            $oTable->SetCellSpacing(1);
+
+            $oTableRow = new TableRow();
+            $oTableRow->SetClass("color4");
+            $oTableRow->AddTextCell("Operating system name");
+            $oTableRow->AddTextCell("Description");
+            $oTableRow->AddTextCell("No. Versions");
+
+            $oTable->SetHeader($oTableRow);
+                    
+            while(list($i, $iAppId) = each($aApps))
+            {
+                $oApp = new Application($iAppId);
+
+                //set row color
+                $sColor = ($i % 2) ? "color0" : "color1";
+
+                $oTableRowHighlight = GetStandardRowHighlight($i);
+
+                $sUrl = $oApp->objectMakeUrl();
+
+                $oTableRowClick = new TableRowClick($sUrl);
+                $oTableRowClick->SetHighlight($oTableRowHighlight);
+                
+                //format desc
+                $sDesc = util_trim_description($oApp->sDescription);
+                
+                //display row
+                $oTableRow = new TableRow();
+                $oTableRow->SetRowClick($oTableRowClick);
+                $oTableRow->SetClass($sColor);
+                $oTableRow->AddTextCell($oApp->objectMakeLink());
+                $oTableRow->AddTextCell("$sDesc &nbsp;");
+                $oTableRow->AddTextCell(sizeof($oApp->aVersionsIds));
+
+                $oTable->AddRow($oTableRow);
+            }
+            
+            // output table
+            echo $oTable->GetString();
+
+            echo html_frame_end( count($aApps) . " operating systems in this system");
+        }
+
+        // Show a message if this category is empty
+        if(!$aApps && !$aSubs)
+        {
+            echo html_frame_start("",'98%','',2);
+            echo "<p><b>System: ". $sCatFullPath ."</b><br>\n";
+            echo html_frame_end();
+
+            echo html_frame_start('','90%','',2);
+            echo 'This system has no sub-systems or operating systems';
+            echo html_frame_end();
+        }
+    }
+}
+
+?>
diff --git a/include/sidebar_admin.php b/include/sidebar_admin.php
index a2bbaba..8ceabc8 100644
--- a/include/sidebar_admin.php
+++ b/include/sidebar_admin.php
@@ -57,6 +57,7 @@ function global_admin_menu() {
     $g->addmisc("&nbsp;");
 
     $g->add("Add Category", BASE."objectManager.php?sClass=category&amp;sAction=add&amp;sTitle=Add+Category");
+    $g->add("Add System", BASE."objectManager.php?sClass=qemuSystem&amp;sAction=add&amp;sTitle=Add+System");
     $g->add("Add Vendor", BASE."objectManager.php?sClass=vendor&amp;bQueue=".
     "false&amp;sAction=add&amp;sTitle=Add%20Vendor");