diff --git a/docs/manual/running.html b/docs/manual/running.html
index ca2d7bdca..2ef471dd0 100644
--- a/docs/manual/running.html
+++ b/docs/manual/running.html
@@ -78,20 +78,21 @@ those without a <code>description</code> are listed as
 <h3><a name="options">Command-line Options Summary</a></h3>
 <pre>ant [options] [target [target2 [target3] ...]]
 Options:
-  -help                  print this message
-  -projecthelp           print project help information
+  -help, -h              print this message
+  -projecthelp, -p       print project help information
   -version               print the version information and exit
   -diagnostics           print information that might be helpful to
                          diagnose or report problems.
   -quiet, -q             be extra quiet
   -verbose, -v           be extra verbose
-  -debug                 print debugging information
-  -emacs                 produce logging information without adornments
-  -lib <path>            specifies a path to search for jars and classes
+  -debug, -d             print debugging information
+  -emacs, -e             produce logging information without adornments
+  -lib &lt;path&gt;            specifies a path to search for jars and classes
   -logfile &lt;file&gt;        use given file for log
     -l     &lt;file&gt;                ''
   -logger &lt;classname&gt;    the class which is to perform logging
   -listener &lt;classname&gt;  add an instance of class as a project listener
+  -noinput               do not allow interactive input
   -buildfile &lt;file&gt;      use given buildfile
     -file    &lt;file&gt;              ''
     -f       &lt;file&gt;              ''
@@ -101,8 +102,10 @@ Options:
   -propertyfile &lt;name&gt;   load all properties from file with -D
                          properties taking precedence
   -inputhandler &lt;class&gt;  the class which will handle input requests
-  -find &lt;file&gt;           search for buildfile towards the root of the
-                         filesystem and use it
+  -find &lt;file&gt;           (s)earch for buildfile towards the root of
+    -s  &lt;file&gt;           the filesystem and use it
+  -nice  number          A niceness value for the main thread:
+                         1 (lowest) to 10 (highest); 5 is the default                         
 </pre>
 <p>For more information about <code>-logger</code> and
 <code>-listener</code> see
diff --git a/src/main/org/apache/tools/ant/Main.java b/src/main/org/apache/tools/ant/Main.java
index b5492dd20..e5fc19780 100644
--- a/src/main/org/apache/tools/ant/Main.java
+++ b/src/main/org/apache/tools/ant/Main.java
@@ -152,6 +152,11 @@ public class Main implements AntMain {
      */
     private static boolean isLogFileUsed = false;
 
+    /**
+     * optional thread priority
+     */
+    private Integer threadPriority=null;
+
     /**
      * Prints the message of the Throwable if it (the message) is not
      * <code>null</code>.
@@ -434,6 +439,23 @@ public class Main implements AntMain {
                 }
             } else if (arg.equals("-k") || arg.equals("-keep-going")) {
                 keepGoingMode = true;
+            } else if (arg.equals("-nice")) {
+                try {
+                    threadPriority=Integer.decode(args[i + 1]);
+                } catch (ArrayIndexOutOfBoundsException aioobe) {
+                    throw new BuildException(
+                            "You must supply a niceness value (1-10)"+
+                            " after the -nice option");
+                } catch (NumberFormatException e) {
+                    throw new BuildException("Unrecognized niceness value: " +
+                            args[i + 1]);
+                }
+                i++;
+                if(threadPriority.intValue()<Thread.MIN_PRIORITY ||
+                        threadPriority.intValue()>Thread.MAX_PRIORITY) {
+                    throw new BuildException(
+                            "Niceness value is out of the range 1-10");
+                }
             } else if (arg.startsWith("-")) {
                 // we don't have any more args to recognize!
                 String msg = "Unknown argument: " + arg;
@@ -632,9 +654,23 @@ public class Main implements AntMain {
                 System.setOut(new PrintStream(new DemuxOutputStream(project, false)));
                 System.setErr(new PrintStream(new DemuxOutputStream(project, true)));
 
+
                 if (!projectHelp) {
                     project.fireBuildStarted();
                 }
+
+                // set the thread priorities
+                if (threadPriority != null) {
+                    try {
+                        project.log("Setting Ant's thread priority to "
+                                + threadPriority,Project.MSG_VERBOSE);
+                        Thread.currentThread().setPriority(threadPriority.intValue());
+                    } catch (SecurityException swallowed) {
+                        //we cannot set the priority here.
+                        project.log("A security manager refused to set the -nice value");
+                    }
+                }
+
                 project.init();
                 project.setUserProperty("ant.version", getAntVersion());
 
@@ -826,6 +862,8 @@ public class Main implements AntMain {
         msg.append("  -inputhandler <class>  the class which will handle input requests" + lSep);
         msg.append("  -find <file>           (s)earch for buildfile towards the root of" + lSep);
         msg.append("    -s  <file>           the filesystem and use it" + lSep);
+        msg.append("  -nice  number          A niceness value for the main thread:" + lSep +
+                   "                         1 (lowest) to 10 (highest); 5 is the default" + lSep);
         System.out.println(msg.toString());
     }