diff -r 6ac37d80ecb7 -r 81cea57bf4e9 rt/vm/src/main/java/org/apidesign/vm4brwsr/ClosureWrapper.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rt/vm/src/main/java/org/apidesign/vm4brwsr/ClosureWrapper.java	Tue Mar 12 13:54:26 2013 +0100
@@ -0,0 +1,90 @@
+/**
+ * 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.vm4brwsr;
+
+import com.google.javascript.jscomp.CommandLineRunner;
+import com.google.javascript.jscomp.SourceFile;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.PrintStream;
+import java.util.Collections;
+import java.util.List;
+import org.apidesign.bck2brwsr.core.ExtraJavaScript;
+
+/**
+ *
+ * @author Jaroslav Tulach <jtulach@netbeans.org>
+ */
+@ExtraJavaScript(processByteCode = false, resource="")
+final class ClosureWrapper extends CommandLineRunner implements SourceFile.Generator {
+    private static final String[] ARGS = { "--compilation_level", "SIMPLE_OPTIMIZATIONS", "--js", "bck2brwsr-raw.js" };
+
+    private String code;
+    private final Bck2Brwsr.Resources res;
+    private final StringArray classes;
+    private ClosureWrapper(Appendable out, Bck2Brwsr.Resources res, StringArray classes) {
+        super(
+            ARGS, 
+            new PrintStream(new APS(out)), System.err
+        );
+        this.res = res;
+        this.classes = classes;
+    }
+
+    @Override
+    protected List<SourceFile> createInputs(List<String> files, boolean allowStdIn) throws FlagUsageException, IOException {
+        if (files.size() != 1 || !"bck2brwsr-raw.js".equals(files.get(0))) {
+            throw new IOException("Unexpected files: " + files);
+        }
+        return Collections.nCopies(1, SourceFile.fromGenerator("bck2brwsr-raw.js", this));
+    }
+
+    @Override
+    public String getCode() {
+        if (code == null) {
+            StringBuilder sb = new StringBuilder();
+            try {
+                VM.compile(res, sb, classes);
+            } catch (IOException ex) {
+                code = ex.getMessage();
+            }
+            code = sb.toString();
+        }
+        return code;
+    }
+    
+    private static final class APS extends OutputStream {
+        private final Appendable out;
+
+        public APS(Appendable out) {
+            this.out = out;
+        }
+        @Override
+        public void write(int b) throws IOException {
+            out.append((char)b);
+        }
+    }
+    static int produceTo(Appendable w, Bck2Brwsr.Resources resources, StringArray arr) throws IOException {
+        ClosureWrapper cw = new ClosureWrapper(w, resources, arr);
+        try {
+            return cw.doRun();
+        } catch (FlagUsageException ex) {
+            throw new IOException(ex);
+        }
+    }
+}