diff -r 000000000000 -r 36746c46716a rt/aot/src/main/java/org/apidesign/bck2brwsr/aot/Bck2BrwsrJars.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rt/aot/src/main/java/org/apidesign/bck2brwsr/aot/Bck2BrwsrJars.java	Mon May 26 17:52:56 2014 +0200
@@ -0,0 +1,157 @@
+/**
+ * Back 2 Browser Bytecode Translator
+ * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. Look for COPYING file in the top folder.
+ * If not, see http://opensource.org/licenses/GPL-2.0.
+ */
+package org.apidesign.bck2brwsr.aot;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.net.URL;
+import java.util.ArrayList;
+import java.util.Enumeration;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.zip.ZipEntry;
+import org.apidesign.vm4brwsr.Bck2Brwsr;
+
+/** Utilities to process JAR files and set a compiler
+ * up 
+ *
+ * @author Jaroslav Tulach
+ */
+public final class Bck2BrwsrJars {
+    private static final Logger LOG = Logger.getLogger(Bck2BrwsrJars.class.getName());
+    
+    private Bck2BrwsrJars() {
+    }
+    
+    /** Creates new compiler pre-configured from the content of 
+     * provided JAR file. The compiler will compile all classes.
+     * The system understands OSGi manifest entries and will export
+     * all packages that are exported in the JAR file. The system
+     * also recognizes META-INF/services and makes sure the file names
+     * are not mangled.
+     * 
+     * @param c the compiler to {@link Bck2Brwsr#addClasses(java.lang.String...) add classes},
+     *    {@link Bck2Brwsr#addResources(java.lang.String...) add resources} and
+     *    {@link Bck2Brwsr#addExported(java.lang.String...) exported objects} to.
+     *    Can be <code>null</code> - in such case an 
+     *    {@link Bck2Brwsr#newCompiler() empty compiler} is constructed.
+     * @param jar the file to process
+     * @return newly configured compiler
+     * @throws IOException if something goes wrong
+     */
+    public static Bck2Brwsr configureFrom(Bck2Brwsr c, File jar) throws IOException {
+        try (JarFile jf = new JarFile(jar)) {
+            List<String> classes = new ArrayList<>();
+            List<String> resources = new ArrayList<>();
+            Set<String> exported = new HashSet<>();
+            
+            listJAR(jf, classes, resources, exported);
+            
+            class JarRes extends EmulationResources implements Bck2Brwsr.Resources {
+
+                @Override
+                public InputStream get(String resource) throws IOException {
+                    InputStream is = jf.getInputStream(new ZipEntry(resource));
+                    return is == null ? super.get(resource) : is;
+                }
+            }
+            return Bck2Brwsr.newCompiler()
+                .library(true)
+                .addClasses(classes.toArray(new String[classes.size()]))
+                .addExported(exported.toArray(new String[exported.size()]))
+                .addResources(resources.toArray(new String[resources.size()]))
+                .resources(new JarRes());
+        }
+    }
+    
+    private static void listJAR(
+        JarFile j, List<String> classes,
+        List<String> resources, Set<String> keep
+    ) throws IOException {
+        Enumeration<JarEntry> en = j.entries();
+        while (en.hasMoreElements()) {
+            JarEntry e = en.nextElement();
+            final String n = e.getName();
+            if (n.endsWith("/")) {
+                continue;
+            }
+            int last = n.lastIndexOf('/');
+            String pkg = n.substring(0, last + 1);
+            if (pkg.startsWith("java/")) {
+                keep.add(pkg);
+            }
+            if (n.endsWith(".class")) {
+                classes.add(n.substring(0, n.length() - 6));
+            } else {
+                resources.add(n);
+                if (n.startsWith("META-INF/services/") && keep != null) {
+                    BufferedReader r = new BufferedReader(new InputStreamReader(j.getInputStream(e)));
+                    for (;;) {
+                        String l = r.readLine();
+                        if (l == null) {
+                            break;
+                        }
+                        if (l.startsWith("#")) {
+                            continue;
+                        }
+                        keep.add(l.replace('.', '/'));
+                    }
+                }
+            }
+        }
+        String exp = j.getManifest().getMainAttributes().getValue("Export-Package");
+        if (exp != null && keep != null) {
+            for (String def : exp.split(",")) {
+                for (String sep : def.split(";")) {
+                    keep.add(sep.replace('.', '/') + "/");
+                    break;
+                }
+            }
+        }
+    }
+
+    static class EmulationResources implements Bck2Brwsr.Resources {
+
+        @Override
+        public InputStream get(String name) throws IOException {
+            Enumeration<URL> en = Bck2BrwsrJars.class.getClassLoader().getResources(name);
+            URL u = null;
+            while (en.hasMoreElements()) {
+                u = en.nextElement();
+            }
+            if (u == null) {
+                LOG.log(Level.WARNING, "Cannot find {0}", name);
+                return null;
+            }
+            if (u.toExternalForm().contains("/rt.jar!")) {
+                LOG.log(Level.WARNING, "{0}No bootdelegation for ", name);
+                return null;
+            }
+            return u.openStream();
+        }
+    }
+    
+}