diff --git a/build.xml b/build.xml
index c2e2481c48..911c75d015 100644
--- a/build.xml
+++ b/build.xml
@@ -451,6 +451,8 @@
     <target name="consoleDocs" depends="deletepkg-temp, prepconsoleDocs">
         <zip destfile="docs.zip" basedir="pkg-temp" whenempty="fail" />
     </target>
+
+    <target name="updater200" depends="prepupdate, preplicenses, pack200, zipit" />
     <target name="updater" depends="prepupdate, preplicenses, zipit" />
     <target name="updaterWithGeoIP" depends="prepupdate, prepgeoupdate, preplicenses, zipit" />
     <target name="updaterWithJetty" depends="prepjupdate, preplicenses, zipit" />
@@ -460,7 +462,19 @@
     <target name="updaterRouter" depends="prepupdateRouter, zipit" />
     <target name="zipit">
         <zip destfile="i2pupdate.zip" basedir="pkg-temp" whenempty="fail" />
+       <!-- just a test, makes almost no difference
+        <tar destfile="i2pupdate.tgz" basedir="pkg-temp" compression="gzip" />
+        <tar destfile="i2pupdate.tbz" basedir="pkg-temp" compression="bzip2" />
+       -->
     </target>
+    <target name="pack200">
+        <exec executable="sh" failifexecutionfails="true">
+            <arg value="-c" />
+            <!-- pack200 will only pack to a .pack file, and only from a .jar file, so we put another .jar on the end -->
+            <arg value="for i in pkg-temp/lib/*.jar pkg-temp/webapps/*war; do echo pack200 $i; mv $i $i.jar; pack200 -g $i.pack $i.jar; rm -f $i.jar; done" />
+        </exec>
+    </target>
+
     <target name="updateTest" depends="prepupdate">
         <ant dir="core/java/" target="jarTest" />    
         <copy file="core/java/build/i2ptest.jar" todir="pkg-temp/lib" />
diff --git a/core/java/src/net/i2p/util/FileUtil.java b/core/java/src/net/i2p/util/FileUtil.java
index fda5066412..ef73113018 100644
--- a/core/java/src/net/i2p/util/FileUtil.java
+++ b/core/java/src/net/i2p/util/FileUtil.java
@@ -12,9 +12,12 @@ import java.io.OutputStream;
 import java.util.ArrayList;
 import java.util.Enumeration;
 import java.util.List;
+import java.util.jar.JarOutputStream;
+import java.util.jar.Pack200;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipFile;
 
+
 /**
  * General helper methods for messing with files
  *
@@ -75,6 +78,10 @@ public class FileUtil {
         }
     }
     
+    /**
+     *  As of release 0.7.12, any files inside the zip that have a .jar.pack or .war.pack suffix
+     *  are transparently unpacked to a .jar or .war file using unpack200.
+     */
     public static boolean extractZip(File zipfile, File targetDir) {
         ZipFile zip = null;
         try {
@@ -109,15 +116,22 @@ public class FileUtil {
                 } else {
                     try {
                         InputStream in = zip.getInputStream(entry);
-                        FileOutputStream fos = new FileOutputStream(target);
-                        int read = 0;
-                        while ( (read = in.read(buf)) != -1) {
-                            fos.write(buf, 0, read);
+                        if (entry.getName().endsWith(".jar.pack") || entry.getName().endsWith(".war.pack")) {
+                            target = new File(targetDir, entry.getName().substring(0, entry.getName().length() - ".pack".length()));
+                            JarOutputStream fos = new JarOutputStream(new FileOutputStream(target));
+                            Pack200.newUnpacker().unpack(in, fos);
+                            fos.close();
+                            System.err.println("INFO: File [" + entry.getName() + "] extracted and unpacked");
+                        } else {
+                            FileOutputStream fos = new FileOutputStream(target);
+                            int read = 0;
+                            while ( (read = in.read(buf)) != -1) {
+                                fos.write(buf, 0, read);
+                            }
+                            fos.close();
+                            System.err.println("INFO: File [" + entry.getName() + "] extracted");
                         }
-                        fos.close();
                         in.close();
-                        
-                        System.err.println("INFO: File [" + entry.getName() + "] extracted");
                     } catch (IOException ioe) {
                         System.err.println("ERROR: Error extracting the zip entry (" + entry.getName() + "]");
                         ioe.printStackTrace();
diff --git a/history.txt b/history.txt
index 895bba302a..07595dd115 100644
--- a/history.txt
+++ b/history.txt
@@ -1,3 +1,9 @@
+2010-02-23 zzz
+    * Unzip: Any files in the zip with a .jar.pack or .war.pack extension
+      will be transparently unpacked with unpack200. Savings is about 60%.
+      Someday we will do this for suds, but we can do it for xpi2ps now.
+    * build: Add updater200 target
+
 2010-02-22 zzz
     * configclients.jsp:
       - Add js delete confirm
diff --git a/router/java/src/net/i2p/router/RouterVersion.java b/router/java/src/net/i2p/router/RouterVersion.java
index 687f8db2f2..8c54ff98c5 100644
--- a/router/java/src/net/i2p/router/RouterVersion.java
+++ b/router/java/src/net/i2p/router/RouterVersion.java
@@ -18,7 +18,7 @@ public class RouterVersion {
     /** deprecated */
     public final static String ID = "Monotone";
     public final static String VERSION = CoreVersion.VERSION;
-    public final static long BUILD = 4;
+    public final static long BUILD = 5;
 
     /** for example "-test" */
     public final static String EXTRA = "";