diff --git a/WHATSNEW b/WHATSNEW
index beaa95df6..bec103137 100644
--- a/WHATSNEW
+++ b/WHATSNEW
@@ -1,4 +1,4 @@
-Changes from Ant 1.5.2 to current CVS version
+Changes from Ant 1.5.3 to current CVS version
 =============================================
 
 Changes that could break older environments:
@@ -163,6 +163,8 @@ Other changes:
 
 * New filterreader <escapeunicode/>.
 
+* Support for HP's NonStop (Tandem) OS has been added.
+
 Changes from Ant 1.5.2 to Ant 1.5.3
 ===================================
 
diff --git a/docs/manual/CoreTasks/chmod.html b/docs/manual/CoreTasks/chmod.html
index 120bd1a3c..cc1aba279 100644
--- a/docs/manual/CoreTasks/chmod.html
+++ b/docs/manual/CoreTasks/chmod.html
@@ -9,7 +9,8 @@
 
 <h2><a name="chmod">Chmod</a></h2>
 <h3>Description</h3>
-<p>Changes the permissions of a file or all files inside specified directories. Right now it has effect only under Unix.
+<p>Changes the permissions of a file or all files inside specified
+directories. Right now it has effect only under Unix or NonStop (Tandem).
 The permissions are also UNIX style, like the argument for the chmod command.</p>
 <p>See the section on <a href="../dirtasks.html#directorybasedtasks">directory based
 tasks</a>, on how the inclusion/exclusion of files works, and how to
@@ -102,7 +103,7 @@ below any directory named trial) writable for members of the same
 group on a UNIX system. In addition all files belonging to a FileSet
 with <code>id</code> <code>other.shared.sources</code> get the same
 permissions.</p>
-<hr><p align="center">Copyright &copy; 2000-2002 Apache Software Foundation. All rights
+<hr><p align="center">Copyright &copy; 2000-2003 Apache Software Foundation. All rights
 Reserved.</p>
 
 </body>
diff --git a/docs/manual/CoreTasks/conditions.html b/docs/manual/CoreTasks/conditions.html
index b8465cf24..f99c88d8f 100644
--- a/docs/manual/CoreTasks/conditions.html
+++ b/docs/manual/CoreTasks/conditions.html
@@ -92,6 +92,7 @@ the tests succeed.
   <li>unix (for all Unix and Unix-like operating systems)</li>
   <li>netware (for Novell NetWare)</li>
   <li>os/2 (for OS/2)</li>
+  <li>tandem (for HP's NonStop - formerly Tandem)</li>
   <li>win9x for Microsoft Windows 95 and 98</li>
   <li>z/os for z/OS and OS/390</li>
   <li>os/400 for OS/400</li>
@@ -315,7 +316,7 @@ that is "true","yes", or "on"</p>
 </table>
 
 <hr>
-<p align="center">Copyright &copy; 2001-2002 Apache Software
+<p align="center">Copyright &copy; 2001-2003 Apache Software
 Foundation. All rights Reserved.</p>
 
 </body>
diff --git a/docs/manual/CoreTasks/pathconvert.html b/docs/manual/CoreTasks/pathconvert.html
index e49e2fe53..b9cd2f4bd 100644
--- a/docs/manual/CoreTasks/pathconvert.html
+++ b/docs/manual/CoreTasks/pathconvert.html
@@ -31,7 +31,7 @@ drive letters to Unix paths, and vice-versa.</p>
     <td valign="top">targetos</td>
     <td valign="top">
         The target architecture.  Must be one of 'unix', 'windows', 
-        'netware' or 'os/2'.
+        'netware', 'tandem' or 'os/2'.
         This is a shorthand mechanism for specifying both
         <code>pathsep</code> and <code>dirsep</code>
         according to the specified target architecture.
@@ -176,7 +176,7 @@ list of files.
 </p>
 
 <hr>
-<p align="center">Copyright &copy; 2001-2002 Apache Software Foundation.
+<p align="center">Copyright &copy; 2001-2003 Apache Software Foundation.
 All rights Reserved.</p>
 </body>
 </html>
diff --git a/src/main/org/apache/tools/ant/taskdefs/Chmod.java b/src/main/org/apache/tools/ant/taskdefs/Chmod.java
index 4bd3cad0d..f8327cb75 100644
--- a/src/main/org/apache/tools/ant/taskdefs/Chmod.java
+++ b/src/main/org/apache/tools/ant/taskdefs/Chmod.java
@@ -1,7 +1,7 @@
 /*
  * The Apache Software License, Version 1.1
  *
- * Copyright (c) 2000-2002 The Apache Software Foundation.  All rights
+ * Copyright (c) 2000-2003 The Apache Software Foundation.  All rights
  * reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -255,6 +255,7 @@ public class Chmod extends ExecuteOn {
     }
 
     protected boolean isValidOs() {
-        return Os.isFamily("unix") && super.isValidOs();
+        return (Os.isFamily("unix") || Os.isFamily("tandem")) 
+            && super.isValidOs();
     }
 }
diff --git a/src/main/org/apache/tools/ant/taskdefs/Execute.java b/src/main/org/apache/tools/ant/taskdefs/Execute.java
index f9d94e9b6..8f96009af 100644
--- a/src/main/org/apache/tools/ant/taskdefs/Execute.java
+++ b/src/main/org/apache/tools/ant/taskdefs/Execute.java
@@ -232,6 +232,10 @@ public class Execute {
         } else if (Os.isFamily("z/os")) {
             String[] cmd = {"/bin/env"};
             return cmd;
+        } else if (Os.isFamily("tandem")) {
+//            String[] cmd = {"/bin/sh -c env"};
+            String[] cmd = {"/bin/env"};
+            return cmd;
         } else if (Os.isFamily("unix")) {
             // Generic UNIX
             // Alternatively one could use: /bin/sh -c env
diff --git a/src/main/org/apache/tools/ant/taskdefs/PathConvert.java b/src/main/org/apache/tools/ant/taskdefs/PathConvert.java
index 77ea7d4a9..86a4c50c5 100644
--- a/src/main/org/apache/tools/ant/taskdefs/PathConvert.java
+++ b/src/main/org/apache/tools/ant/taskdefs/PathConvert.java
@@ -1,7 +1,7 @@
 /*
  * The Apache Software License, Version 1.1
  *
- * Copyright (c) 2001-2002 The Apache Software Foundation.  All rights
+ * Copyright (c) 2001-2003 The Apache Software Foundation.  All rights
  * reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -202,7 +202,7 @@ public class PathConvert extends Task {
      */
     public static class TargetOs extends EnumeratedAttribute {
         public String[] getValues() {
-            return new String[]{"windows", "unix", "netware", "os/2"};
+            return new String[]{"windows", "unix", "netware", "os/2", "tandem"};
         }
     }
 
@@ -269,7 +269,7 @@ public class PathConvert extends Task {
         // validateSetup code, the same assumptions can be made as
         // with windows - that ; is the path separator
 
-        targetWindows = !targetOS.equals("unix");
+        targetWindows = !targetOS.equals("unix") && !targetOS.equals("tandem");
     }
 
     /**
diff --git a/src/main/org/apache/tools/ant/taskdefs/condition/Os.java b/src/main/org/apache/tools/ant/taskdefs/condition/Os.java
index a0fd1828e..5106f4d63 100644
--- a/src/main/org/apache/tools/ant/taskdefs/condition/Os.java
+++ b/src/main/org/apache/tools/ant/taskdefs/condition/Os.java
@@ -95,6 +95,7 @@ public class Os implements Condition {
      *               <li>mac</li>
      *               <li>netware</li>
      *               <li>os/2</li>
+     *               <li>tandem</li>
      *               <li>unix</li>
      *               <li>windows</li>
      *               <li>win9x</li>
@@ -214,6 +215,8 @@ public class Os implements Condition {
                     isFamily = pathSep.equals(";") && !isFamily("netware");
                 } else if (family.equals("mac")) {
                     isFamily = osName.indexOf("mac") > -1;
+                } else if (family.equals("tandem")) {
+                    isFamily = osName.indexOf("nonstop_kernel") > -1;
                 } else if (family.equals("unix")) {
                     isFamily = pathSep.equals(":")
                         && (!isFamily("mac") || osName.endsWith("x"));