Index: plugins/skinx/src/main/java/com/xpn/xwiki/web/sx/SxResourceSource.java
===================================================================
--- plugins/skinx/src/main/java/com/xpn/xwiki/web/sx/SxResourceSource.java	(revision 25712)
+++ plugins/skinx/src/main/java/com/xpn/xwiki/web/sx/SxResourceSource.java	(working copy)
@@ -31,7 +31,7 @@
  * @version $Id$
  * @since 1.7M2
  */
-public class SxResourceSource implements SxSource
+public class SxResourceSource extends AbstractSxSource
 {
     /**
      * The full path of the resource to use as extension. Exemple: path/to/hello.js
Index: plugins/skinx/src/main/java/com/xpn/xwiki/web/sx/SxDocumentSource.java
===================================================================
--- plugins/skinx/src/main/java/com/xpn/xwiki/web/sx/SxDocumentSource.java	(revision 25712)
+++ plugins/skinx/src/main/java/com/xpn/xwiki/web/sx/SxDocumentSource.java	(working copy)
@@ -27,6 +27,7 @@
 import com.xpn.xwiki.XWikiContext;
 import com.xpn.xwiki.doc.XWikiDocument;
 import com.xpn.xwiki.objects.BaseObject;
+import org.xwiki.bridge.DocumentName;
 
 /**
  * Wiki Document source for Skin Extensions. This is the standard source for Skin Extensions, using an XWiki object of
@@ -35,7 +36,7 @@
  * @version $Id$
  * @since 1.7M2
  */
-public class SxDocumentSource implements SxSource
+public class SxDocumentSource extends AbstractSxSource
 {
     /** The name of the property in the script extension object which contains the script content. */
     private static final String CONTENT_PROPERTY_NAME = "code";
@@ -142,4 +143,14 @@
         return this.document.getDate().getTime();
     }
 
+    /**
+     * {@inheritDoc}
+     * 
+     * @see SxSource#getDocumentName()
+     */
+    public DocumentName getDocumentName()
+    {
+        return this.document.getDocumentName();
+    }
+
 }
Index: plugins/skinx/src/main/java/com/xpn/xwiki/web/sx/SxSource.java
===================================================================
--- plugins/skinx/src/main/java/com/xpn/xwiki/web/sx/SxSource.java	(revision 25712)
+++ plugins/skinx/src/main/java/com/xpn/xwiki/web/sx/SxSource.java	(working copy)
@@ -20,6 +20,10 @@
  */
 package com.xpn.xwiki.web.sx;
 
+import java.util.Date;
+
+import org.xwiki.bridge.DocumentName;
+
 /**
  * Skin extension source. Can be a document, a resource file, or anything else.
  * 
@@ -35,25 +39,46 @@
     {
         /** 
          * Cache for a long time.
-         * @see AbstractSxAction#LONG_CACHE_DURATION 
+         * @see AbstractSxSource#LONG_CACHE_DURATION 
          */
-        LONG,
+        LONG(30 * 24 * 3600 * 1000L),
 
         /** 
          * Cache for a short time.
-         * @see AbstractSxAction#SHORT_CACHE_DURATION
+         * @see AbstractSxSource#SHORT_CACHE_DURATION
          */
-        SHORT,
+        SHORT(1 * 24 * 3600 * 1000L),
 
         /** 
          * Cache for the proxy/browser's default time, It will be held in the 
-         * server cache an amount of time specified in AbstractSxAction.
-         * @see AbstractSxAction.DEFAULT_CACHE_DURATION 
+         * server cache an amount of time specified in AbstractSxSource.
+         * @see AbstractSxSource.DEFAULT_CACHE_DURATION 
          */
-        DEFAULT,
+        DEFAULT(1 * 24 * 3600 * 1000L),
 
         /** Do not cache at all in server cache or in proxy/browser. */
-        FORBID
+        FORBID(0x0000000000000000L);
+
+        /** How many milliseconds this cache should last for. */
+        private final long cacheDuration;
+
+        /**
+         * Private Constructor.
+         *
+         * @param duration How many milliseconds this cache should last for.
+         */
+        private CachePolicy(long duration)
+        {
+            cacheDuration = duration;
+        }
+
+        /**
+         * @return The time when caches with this policy should expire if they start now
+         */
+        public long getExpirationTime()
+        {
+            return new Date().getTime() + cacheDuration;
+        }
     }
 
     /**
@@ -71,4 +96,13 @@
      */
     CachePolicy getCachePolicy();
 
+    /**
+     * @return The DocumentName of the document from which this script was taken or null of not applicable.
+     */
+    DocumentName getDocumentName();
+
+    /**
+     * @return The time when caches of this source should expire
+     */
+    long getExpirationTime();
 }
Index: plugins/skinx/src/main/java/com/xpn/xwiki/web/sx/AbstractSxAction.java
===================================================================
--- plugins/skinx/src/main/java/com/xpn/xwiki/web/sx/AbstractSxAction.java	(revision 25712)
+++ plugins/skinx/src/main/java/com/xpn/xwiki/web/sx/AbstractSxAction.java	(working copy)
@@ -21,7 +21,6 @@
 package com.xpn.xwiki.web.sx;
 
 import java.io.IOException;
-import java.util.Date;
 
 import javax.servlet.http.HttpServletResponse;
 
@@ -32,7 +31,6 @@
 import com.xpn.xwiki.XWikiContext;
 import com.xpn.xwiki.XWikiException;
 import com.xpn.xwiki.web.XWikiAction;
-import com.xpn.xwiki.web.XWikiRequest;
 import com.xpn.xwiki.web.XWikiResponse;
 import com.xpn.xwiki.web.sx.SxSource.CachePolicy;
 
@@ -45,12 +43,6 @@
  */
 public abstract class AbstractSxAction extends XWikiAction
 {
-    /** How many milliseconds a file should be cached for if it sets CachePolicy to LONG, hardcoded to 30 days. */
-    private static final long LONG_CACHE_DURATION = 30 * 24 * 3600 * 1000L;
-
-    /** How many milliseconds a file should be cached for if it sets CachePolicy to SHORT, hardcoded to 1 day. */
-    private static final long SHORT_CACHE_DURATION = 1 * 24 * 3600 * 1000L;
-
     /** What http header parameter is used to specify when a file was last modified. */
     private static final String LAST_MODIFIED_HEADER = "Last-Modified";
 
@@ -69,6 +61,9 @@
     /** If the user specifies this url parameter equals false, we will send uncompressed script content. */
     private static final String COMPRESS_SCRIPT_REQUEST_PARAMETER = "minify";
 
+    /** Static instance of SxCache, lazy initialized because we need the context to get the desired capacity. */
+    private static SxCache sxCache;
+
     /** @return the logging object of the concrete subclass. */
     protected abstract Log getLog();
 
@@ -84,7 +79,6 @@
     public void renderExtension(SxSource sxSource, Extension sxType, XWikiContext context)
         throws XWikiException
     {
-        XWikiRequest request = context.getRequest();
         XWikiResponse response = context.getResponse();
 
         String extensionContent = sxSource.getContent();
@@ -99,20 +93,14 @@
 
         if (cachePolicy != CachePolicy.FORBID) {
             response.setHeader(CACHE_CONTROL_HEADER, "public");
-        }
-        if (cachePolicy == CachePolicy.LONG) {
-            // Cache for one month (30 days)
-            response.setDateHeader(CACHE_EXPIRES_HEADER, (new Date()).getTime() + LONG_CACHE_DURATION);
-        } else if (cachePolicy == CachePolicy.SHORT) {
-            // Cache for one day
-            response.setDateHeader(CACHE_EXPIRES_HEADER, (new Date()).getTime() + SHORT_CACHE_DURATION);
-        } else if (cachePolicy == CachePolicy.FORBID) {
+            if (cachePolicy != CachePolicy.DEFAULT) {
+                response.setHeader(CACHE_EXPIRES_HEADER, (Long.toString(sxSource.getExpirationTime())));
+            }
+        } else {
             response.setHeader(CACHE_CONTROL_HEADER, "no-cache, no-store, must-revalidate");
         }
 
-        if (BooleanUtils.toBoolean(StringUtils.defaultIfEmpty(
-                        request.get(COMPRESS_SCRIPT_REQUEST_PARAMETER), "true")))
-        {
+        if (!(sxSource instanceof SxCacheableSource) && skipCompressionRequested(context)) {
             extensionContent = sxType.getCompressor().compress(extensionContent);
         }
 
@@ -133,16 +121,31 @@
     @Override
     public String render(XWikiContext context) throws XWikiException
     {
-        SxSource sxSource;
+        synchronized (this) {
+            if (sxCache == null) {
+                sxCache = SxCache.newInstance(context);
+            }
+        }
+        SxSource sxSource = sxCache.get(context.getURL().toString());
 
-        if (context.getRequest().getParameter(JAR_RESOURCE_REQUEST_PARAMETER) != null) {
-            sxSource = new SxResourceSource(context.getRequest().getParameter(JAR_RESOURCE_REQUEST_PARAMETER));
-        } else {
-            if (context.getDoc().isNew()) {
-                context.getResponse().setStatus(HttpServletResponse.SC_NOT_FOUND);
-                return "docdoesnotexist";
+        boolean userWantsUncompressed = skipCompressionRequested(context);
+        if (sxSource == null || userWantsUncompressed) {
+            if (context.getRequest().getParameter(JAR_RESOURCE_REQUEST_PARAMETER) != null) {
+                sxSource = new SxResourceSource(context.getRequest().getParameter(JAR_RESOURCE_REQUEST_PARAMETER));
+            } else {
+                if (context.getDoc().isNew()) {
+                    context.getResponse().setStatus(HttpServletResponse.SC_NOT_FOUND);
+                    return "docdoesnotexist";
+                }
+                sxSource = new SxDocumentSource(context, getExtensionType());
             }
-            sxSource = new SxDocumentSource(context, getExtensionType());
+            // There is no point in caching an uncompressed script since the cache is always compressed
+            // so if the user did not want an uncompressed script, we assume the cache needed updating.
+            if (!userWantsUncompressed) {
+                SxCacheableSource cacheSx = new DefaultSxCacheableSource(sxSource, getExtensionType());
+                sxCache.put(context.getURL().toString(), cacheSx);
+                sxSource = cacheSx;
+            }
         }
 
         try {
@@ -161,4 +164,22 @@
      */
     public abstract Extension getExtensionType();
 
+    /**
+     * Get Whether or not the user has requested an uncompressed version of the script.
+     *
+     * @param context The XWikiContext
+     * @return does the user want an uncompressed (origional format) script?
+     */
+    private boolean skipCompressionRequested(XWikiContext context)
+    {
+        if (!BooleanUtils.toBoolean(
+                    StringUtils.defaultIfEmpty(context.getRequest().get(COMPRESS_SCRIPT_REQUEST_PARAMETER), "true")))
+        {
+            if (getLog().isDebugEnabled()) {
+                getLog().debug("The user has requested an uncompressed version of a script");
+            }
+            return true;
+        }
+        return false;
+    }
 }
Index: plugins/skinx/pom.xml
===================================================================
--- plugins/skinx/pom.xml	(revision 25712)
+++ plugins/skinx/pom.xml	(working copy)
@@ -40,7 +40,7 @@
     <dependency>
       <groupId>com.xpn.xwiki.platform</groupId>
       <artifactId>xwiki-core</artifactId>
-      <version>${platform.core.version}</version>
+      <version>2.2-SNAPSHOT</version>
       <scope>provided</scope>
     </dependency>
     <dependency>
Index: tools/xwiki-configuration-resources/src/main/resources/xwiki.cfg.vm
===================================================================
--- tools/xwiki-configuration-resources/src/main/resources/xwiki.cfg.vm	(revision 25712)
+++ tools/xwiki-configuration-resources/src/main/resources/xwiki.cfg.vm	(working copy)
@@ -556,6 +556,14 @@
 #-# Default: 0
 # xwiki.plugin.activitystream.daystokeepevents=0
 
+#-# Skin Extension plugin.
+#-# The Skinx plugin provides a way to get scripts such as CSS or Javascript to the browser from objects attached to
+#-# or from resources within JAR files. The Skinx plugin impliments a cache which stores the scripts in minified form.
+#-#
+#-# The capacity (number of scripts which may be held) in the Skinx cache (Default is 50).
+# xwiki.plugin.skinx.cache.capacity=50
+
+
 #---------------------------------------
 # Misc
 #