Index: src/main/org/apache/tools/ant/taskdefs/XSLTLiaison4.java
===================================================================
--- src/main/org/apache/tools/ant/taskdefs/XSLTLiaison4.java	(revision 0)
+++ src/main/org/apache/tools/ant/taskdefs/XSLTLiaison4.java	(working copy)
@@ -0,0 +1,41 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+package org.apache.tools.ant.taskdefs;
+
+/**
+ * Extends Proxy interface for XSLT processors: adds support for XSLT parameters
+ * of various types (not only String)
+ *
+ *
+ * @see XSLTProcess
+ * @author Frantisek Kucera (xkucf03)
+ * @since Ant 1.9.2
+ */
+public interface XSLTLiaison4 extends XSLTLiaison3 {
+
+    /**
+     * Add a parameter to be set during the XSL transformation.
+     *
+     * @param name the parameter name.
+     * @param value the parameter value as String, Boolean, int, etc.
+     * @throws Exception thrown if any problems happens.
+     * @since Ant 1.9.2
+     * @see Transformer#setParameter(java.lang.String, java.lang.Object)
+     */
+    void addParam(String name, Object value) throws Exception;
+}
Index: src/main/org/apache/tools/ant/taskdefs/optional/TraXLiaison.java
===================================================================
--- src/main/org/apache/tools/ant/taskdefs/optional/TraXLiaison.java	(revision 1532335)
+++ src/main/org/apache/tools/ant/taskdefs/optional/TraXLiaison.java	(working copy)
@@ -47,7 +47,7 @@
 import javax.xml.transform.TransformerConfigurationException;
 import org.apache.tools.ant.BuildException;
 import org.apache.tools.ant.Project;
-import org.apache.tools.ant.taskdefs.XSLTLiaison3;
+import org.apache.tools.ant.taskdefs.XSLTLiaison4;
 import org.apache.tools.ant.taskdefs.XSLTLogger;
 import org.apache.tools.ant.taskdefs.XSLTLoggerAware;
 import org.apache.tools.ant.taskdefs.XSLTProcess;
@@ -68,7 +68,7 @@
  *
  * @since Ant 1.3
  */
-public class TraXLiaison implements XSLTLiaison3, ErrorListener, XSLTLoggerAware {
+public class TraXLiaison implements XSLTLiaison4, ErrorListener, XSLTLoggerAware {
 
     /**
      * Helper for transforming filenames to URIs.
@@ -118,7 +118,7 @@
     private Vector outputProperties = new Vector();
 
     /** stylesheet parameters */
-    private Hashtable params = new Hashtable();
+    private Hashtable<String, Object> params = new Hashtable<String, Object>();
 
     /** factory attributes */
     private Vector attributes = new Vector();
@@ -369,7 +369,7 @@
         for (final Enumeration enumeration = params.keys();
              enumeration.hasMoreElements();) {
             final String name = (String) enumeration.nextElement();
-            final String value = (String) params.get(name);
+            final Object value = params.get(name);
             transformer.setParameter(name, value);
         }
     }
@@ -505,6 +505,15 @@
     public void addParam(String name, String value) {
         params.put(name, value);
     }
+    
+    /**
+     * Add a parameter.
+     * @param name the name of the parameter
+     * @param value the value of the parameter
+     */
+    public void addParam(String name, Object value) {
+        params.put(name, value);
+    }
 
     /**
      * Set a logger.
Index: src/main/org/apache/tools/ant/taskdefs/XSLTLiaison.java
===================================================================
--- src/main/org/apache/tools/ant/taskdefs/XSLTLiaison.java	(revision 1532335)
+++ src/main/org/apache/tools/ant/taskdefs/XSLTLiaison.java	(working copy)
@@ -51,6 +51,7 @@
      * @param name the parameter name.
      * @param expression the parameter value as an expression string.
      * @throws Exception thrown if any problems happens.
+     * @see XSLTLiaison4#addParam(java.lang.String, java.lang.Object) 
      * @since Ant 1.3
      */
     void addParam(String name, String expression) throws Exception;
Index: src/main/org/apache/tools/ant/taskdefs/XSLTProcess.java
===================================================================
--- src/main/org/apache/tools/ant/taskdefs/XSLTProcess.java	(revision 1532335)
+++ src/main/org/apache/tools/ant/taskdefs/XSLTProcess.java	(working copy)
@@ -18,8 +18,20 @@
 package org.apache.tools.ant.taskdefs;
 
 import java.io.File;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.EnumMap;
 import java.util.Enumeration;
+import java.util.List;
+import java.util.Map;
 import java.util.Vector;
+import javax.xml.namespace.QName;
+import javax.xml.xpath.XPath;
+import javax.xml.xpath.XPathConstants;
+import javax.xml.xpath.XPathExpression;
+import javax.xml.xpath.XPathExpressionException;
+import javax.xml.xpath.XPathFactory;
+import javax.xml.xpath.XPathVariableResolver;
 import org.apache.tools.ant.AntClassLoader;
 import org.apache.tools.ant.BuildException;
 import org.apache.tools.ant.DirectoryScanner;
@@ -76,7 +88,7 @@
     private String fileDirParameter = null;
 
     /** additional parameters to be passed to the stylesheets */
-    private Vector params = new Vector();
+    private List<Param> params = new ArrayList<Param>();
 
     /** Input XML document to be used */
     private File inFile = null;
@@ -196,6 +208,19 @@
      * @since Ant 1.8.0
      */
     private boolean failOnNoResources = true;
+    
+    /**
+     * For evaluating template params
+     *
+     * @since Ant 1.9.2
+     */
+    private XPathFactory xpathFactory;
+    /**
+     * For evaluating template params
+     *
+     * @since Ant 1.9.2
+     */
+    private XPath xpath;
 
     /**
      * System properties to set during transformation.
@@ -305,8 +330,9 @@
      * Executes the task.
      *
      * @exception BuildException if there is an execution problem.
-     * @todo validate that if either in or our is defined, then both are
+     * @todo validate that if either in or out is defined, then both are
      */
+    @Override
     public void execute() throws BuildException {
         if ("style".equals(getTaskType())) {
             log("Warning: the task name <style> is deprecated. Use <xslt> instead.",
@@ -937,7 +963,7 @@
      */
     public Param createParam() {
         Param p = new Param();
-        params.addElement(p);
+        params.add(p);
         return p;
     }
 
@@ -950,6 +976,12 @@
 
         /** The parameter's value */
         private String expression = null;
+        
+        /**
+         * Type of the expression.
+         * @see ParamType
+         */
+        private String type;
 
         private Object ifCond;
         private Object unlessCond;
@@ -974,15 +1006,23 @@
         }
 
         /**
-         * The parameter value
-         * NOTE : was intended to be an XSL expression.
-         * @param expression the parameter's value.
+         * The parameter value - can be a primitive value or XPath expression.
+         * @param expression the parameter's value/expression.
+         * @see #setType(java.lang.String) 
          */
         public void setExpression(String expression) {
             this.expression = expression;
         }
 
         /**
+         * @see ParamType
+         * @since Ant 1.9.2
+         */
+        public void setType(String type) {
+            this.type = type;
+        }
+        
+        /**
          * Get the parameter name
          *
          * @return the parameter name
@@ -1000,6 +1040,7 @@
          *
          * @return the parameter value
          * @exception BuildException if the value is not set.
+         * @see #getType()
          */
         public String getExpression() throws BuildException {
             if (expression == null) {
@@ -1009,6 +1050,14 @@
         }
 
         /**
+         * @see ParamType
+         * @since Ant 1.9.2
+         */
+        public String getType() {
+            return type;
+        }
+
+        /**
          * Set whether this param should be used.  It will be used if
          * the expression evaluates to true or the name of a property
          * which has been set, otherwise it won't.
@@ -1061,7 +1110,58 @@
                 && ph.testUnlessCondition(unlessCond);
         }
     } // Param
+    
+    /**
+     * Enum for types of the parameter expression.
+     *
+     * The expression can be:
+     * <ul>
+     * <li>primitive type that will be parsed from the string value e.g.
+     * {@linkplain Integer#parseInt(java.lang.String)}</li>
+     * <li>XPath expression that will be evaluated (outside of the transformed
+     * document - on empty one) and casted to given type. Inside XPath
+     * expressions the Ant variables (properties) can be used (as XPath
+     * variables - e.g. $variable123). n.b. placeholders in form of
+     * ${variable123} will be replaced with their values before evaluating the
+     * XPath expression (so it can be used for dynamic XPath function names and
+     * other hacks).</li>
+     * </ul>
+     * The parameter will be then passed to the XSLT template.
+     *
+     * Default type (if omited) is primitive String. So if the expression is e.g
+     * "true" with no type, in XSLT it will be only a text string, not true
+     * boolean.
+     *
+     * @see Param#setType(java.lang.String)
+     * @see Param#setExpression(java.lang.String)
+     * @since Ant 1.9.2
+     */
+    public enum ParamType {
 
+        STRING,
+        BOOLEAN,
+        INT,
+        LONG,
+        DOUBLE,
+        XPATH_STRING,
+        XPATH_BOOLEAN,
+        XPATH_NUMBER,
+        XPATH_NODE,
+        XPATH_NODESET;
+        
+        public static final Map<ParamType, QName> XPATH_TYPES;
+
+        static {
+            Map<ParamType, QName> m = new EnumMap<ParamType, QName>(ParamType.class);
+            m.put(XPATH_STRING, XPathConstants.STRING);
+            m.put(XPATH_BOOLEAN, XPathConstants.BOOLEAN);
+            m.put(XPATH_NUMBER, XPathConstants.NUMBER);
+            m.put(XPATH_NODE, XPathConstants.NODE);
+            m.put(XPATH_NODESET, XPathConstants.NODESET);
+            XPATH_TYPES = Collections.unmodifiableMap(m);
+        }
+    }
+
     /**
      * Create an instance of an output property to be configured.
      * @return the newly created output property.
@@ -1119,12 +1219,22 @@
     }
 
     /**
-     * Initialize internal instance of XMLCatalog
+     * Initialize internal instance of XMLCatalog.
+     * Initialize XPath for parameter evaluation.
      * @throws BuildException on error
      */
+    @Override
     public void init() throws BuildException {
         super.init();
         xmlCatalog.setProject(getProject());
+        
+        xpathFactory = XPathFactory.newInstance();
+        xpath = xpathFactory.newXPath();
+        xpath.setXPathVariableResolver(new XPathVariableResolver() {
+            public Object resolveVariable(QName variableName) {
+                return getProject().getProperty(variableName.toString());
+            }
+        });
     }
 
     /**
@@ -1179,10 +1289,21 @@
                     return;
                 }
             }
-            for (Enumeration e = params.elements(); e.hasMoreElements();) {
-                Param p = (Param) e.nextElement();
+            for (Param p : params) {
                 if (p.shouldUse()) {
-                    liaison.addParam(p.getName(), p.getExpression());
+                    Object evaluatedParam = evaluateParam(p);
+                    if (liaison instanceof XSLTLiaison4) {
+                        ((XSLTLiaison4)liaison).addParam(p.getName(), evaluatedParam);
+                    } else {
+                        if (evaluatedParam == null || evaluatedParam instanceof String) {
+                            liaison.addParam(p.getName(), (String)evaluatedParam);
+                        } else {
+                            log("XSLTLiaison '" + liaison.getClass().getName()
+                                    + "' supports only String parameters. Converting parameter '" + p.getName()
+                                    + "' to its String value '" + evaluatedParam, Project.MSG_WARN);
+                            liaison.addParam(p.getName(), String.valueOf(evaluatedParam));
+                        }
+                    }
                 }
             }
         } catch (Exception ex) {
@@ -1190,7 +1311,57 @@
             handleTransformationError(ex);
         }
     }
+    
+    /**
+     * Evaluates parameter expression according to its type.
+     *
+     * @param param parameter from Ant build file
+     * @return value to be passed to XSLT as parameter
+     * @throws IllegalArgumentException if param type is unsupported
+     * @throws NumberFormatException if expression of numeric type is not
+     * desired numeric type
+     * @throws XPathExpressionException if XPath expression can not be compiled
+     * @since Ant 1.9.2
+     */
+    private Object evaluateParam(Param param) throws XPathExpressionException {
+        String typeName = param.getType();
+        String expression = param.getExpression();
 
+        ParamType type;
+
+        if (typeName == null || typeName.isEmpty()) {
+            type = ParamType.STRING; // String is default
+        } else {
+            try {
+                type = ParamType.valueOf(typeName);
+            } catch (IllegalArgumentException e) {
+                throw new IllegalArgumentException("Invalid XSLT parameter type: " + typeName, e);
+            }
+        }
+
+        switch (type) {
+            case STRING:
+                return expression;
+            case BOOLEAN:
+                return Boolean.parseBoolean(expression);
+            case DOUBLE:
+                return Double.parseDouble(expression);
+            case INT:
+                return Integer.parseInt(expression);
+            case LONG:
+                return Long.parseLong(expression);
+            default: // XPath expression
+                QName xpathType = ParamType.XPATH_TYPES.get(type);
+                if (xpathType == null) {
+                    throw new IllegalArgumentException("Invalid XSLT parameter type: " + typeName);
+                } else {
+                    XPathExpression xpe = xpath.compile(expression);
+                    // null = evaluate XPath on empty XML document
+                    return xpe.evaluate((Object) null, xpathType);
+                }
+        }
+    }
+
     /**
      * Sets file parameter(s) for directory and filename if the attribute
      * 'filenameparameter' or 'filedirparameter' are set in the task.