diff --git a/IPython/html/nbconvert/handlers.py b/IPython/html/nbconvert/handlers.py
index 749cd9d..63ba266 100644
--- a/IPython/html/nbconvert/handlers.py
+++ b/IPython/html/nbconvert/handlers.py
@@ -43,7 +43,7 @@ def respond_zip(handler, name, output, resources):
     # Prepare the zip file
     buffer = io.BytesIO()
     zipf = zipfile.ZipFile(buffer, mode='w', compression=zipfile.ZIP_DEFLATED)
-    output_filename = os.path.splitext(name)[0] + '.' + resources['output_extension']
+    output_filename = os.path.splitext(name)[0] + resources['output_extension']
     zipf.writestr(output_filename, cast_bytes(output, 'utf-8'))
     for filename, data in output_files.items():
         zipf.writestr(os.path.basename(filename), data)
@@ -96,7 +96,7 @@ class NbconvertFileHandler(IPythonHandler):
 
         # Force download if requested
         if self.get_argument('download', 'false').lower() == 'true':
-            filename = os.path.splitext(name)[0] + '.' + resources['output_extension']
+            filename = os.path.splitext(name)[0] + resources['output_extension']
             self.set_header('Content-Disposition',
                                'attachment; filename="%s"' % filename)
 
diff --git a/IPython/html/static/notebook/js/menubar.js b/IPython/html/static/notebook/js/menubar.js
index 5992e0f..9a2814b 100644
--- a/IPython/html/static/notebook/js/menubar.js
+++ b/IPython/html/static/notebook/js/menubar.js
@@ -69,17 +69,21 @@ define([
     MenuBar.prototype._nbconvert = function (format, download) {
         download = download || false;
         var notebook_path = this.notebook.notebook_path;
-        if (this.notebook.dirty) {
-            this.notebook.save_notebook({async : false});
-        }
         var url = utils.url_join_encode(
             this.base_url,
             'nbconvert',
             format,
             notebook_path
         ) + "?download=" + download.toString();
-
-        window.open(url);
+        
+        var w = window.open()
+        if (this.notebook.dirty) {
+            this.notebook.save_notebook().then(function() {
+                w.location = url;
+            });
+        } else {
+            w.location = url;
+        }
     };
 
     MenuBar.prototype.bind_events = function () {
@@ -129,10 +133,6 @@ define([
             that._nbconvert('html', false);
         });
 
-        this.element.find('#download_py').click(function () {
-            that._nbconvert('python', true);
-        });
-
         this.element.find('#download_html').click(function () {
             that._nbconvert('html', true);
         });
@@ -308,6 +308,16 @@ define([
         this.events.on('checkpoint_created.Notebook', function (event, data) {
             that.update_restore_checkpoint(that.notebook.checkpoints);
         });
+        
+        this.events.on('notebook_loaded.Notebook', function() {
+            var langinfo = that.notebook.metadata.language_info || {};
+            that.update_nbconvert_script(langinfo);
+        });
+        
+        this.events.on('kernel_ready.Kernel', function(event, data) {
+            var langinfo = data.kernel.info_reply.language_info || {};
+            that.update_nbconvert_script(langinfo);
+        });
     };
 
     MenuBar.prototype.update_restore_checkpoint = function(checkpoints) {
@@ -340,6 +350,31 @@ define([
             );
         });
     };
+    
+    MenuBar.prototype.update_nbconvert_script = function(langinfo) {
+        // Set the 'Download as foo' menu option for the relevant language.
+        var el = this.element.find('#download_script');
+        var that = this;
+        
+        // Set menu entry text to e.g. "Python (.py)"
+        var langname = (langinfo.name || 'Script')
+        langname = langname.charAt(0).toUpperCase()+langname.substr(1) // Capitalise
+        el.find('a').text(langname + ' ('+(langinfo.file_extension || 'txt')+')');
+        
+        // Unregister any previously registered handlers
+        el.off('click');
+        if (langinfo.nbconvert_exporter) {
+            // Metadata specifies a specific exporter, e.g. 'python'
+            el.click(function() {
+                that._nbconvert(langinfo.nbconvert_exporter, true);
+            });
+        } else {
+            // Use generic 'script' exporter
+            el.click(function() {
+                that._nbconvert('script', true);
+            });
+        }
+    };
 
     // Backwards compatability.
     IPython.MenuBar = MenuBar;
diff --git a/IPython/html/static/notebook/js/notebook.js b/IPython/html/static/notebook/js/notebook.js
index b2f56b7..e1db7ad 100644
--- a/IPython/html/static/notebook/js/notebook.js
+++ b/IPython/html/static/notebook/js/notebook.js
@@ -1944,7 +1944,7 @@ define([
         var start =  new Date().getTime();
 
         var that = this;
-        this.contents.save(this.notebook_path, model).then(
+        return this.contents.save(this.notebook_path, model).then(
                 $.proxy(this.save_notebook_success, this, start),
                 function (error) {
                     that.events.trigger('notebook_save_failed.Notebook', error);
diff --git a/IPython/html/templates/notebook.html b/IPython/html/templates/notebook.html
index 4a9a890..1f8b554 100644
--- a/IPython/html/templates/notebook.html
+++ b/IPython/html/templates/notebook.html
@@ -105,7 +105,7 @@ class="notebook_app"
                         <li class="dropdown-submenu"><a href="#">Download as</a>
                             <ul class="dropdown-menu">
                                 <li id="download_ipynb"><a href="#">IPython Notebook (.ipynb)</a></li>
-                                <li id="download_py"><a href="#">Python (.py)</a></li>
+                                <li id="download_script"><a href="#">Script</a></li>
                                 <li id="download_html"><a href="#">HTML (.html)</a></li>
                                 <li id="download_rst"><a href="#">reST (.rst)</a></li>
                                 <li id="download_pdf"><a href="#">PDF (.pdf)</a></li>
diff --git a/IPython/kernel/zmq/ipkernel.py b/IPython/kernel/zmq/ipkernel.py
index d64b521..5cc0a01 100644
--- a/IPython/kernel/zmq/ipkernel.py
+++ b/IPython/kernel/zmq/ipkernel.py
@@ -75,6 +75,8 @@ class IPythonKernel(KernelBase):
                      'codemirror_mode': {'name': 'ipython',
                                          'version': sys.version_info[0]},
                      'pygments_lexer': 'ipython%d' % (3 if PY3 else 2),
+                     'nbconvert_exporter': 'python',
+                     'file_extension': '.py'
                     }
     @property
     def banner(self):
diff --git a/IPython/nbconvert/exporters/export.py b/IPython/nbconvert/exporters/export.py
index f342eb4..6e23738 100644
--- a/IPython/nbconvert/exporters/export.py
+++ b/IPython/nbconvert/exporters/export.py
@@ -19,6 +19,7 @@ from .markdown import MarkdownExporter
 from .python import PythonExporter
 from .rst import RSTExporter
 from .notebook import NotebookExporter
+from .script import ScriptExporter
 
 #-----------------------------------------------------------------------------
 # Classes
@@ -74,6 +75,7 @@ __all__ = [
     'export_pdf',
     'export_markdown',
     'export_python',
+    'export_script',
     'export_rst',
     'export_by_name',
     'get_export_names',
@@ -132,6 +134,7 @@ exporter_map = dict(
     python=PythonExporter,
     rst=RSTExporter,
     notebook=NotebookExporter,
+    script=ScriptExporter,
 )
 
 def _make_exporter(name, E):
diff --git a/IPython/nbconvert/exporters/exporter.py b/IPython/nbconvert/exporters/exporter.py
index a6c00fd..33991db 100644
--- a/IPython/nbconvert/exporters/exporter.py
+++ b/IPython/nbconvert/exporters/exporter.py
@@ -32,7 +32,7 @@ class Exporter(LoggingConfigurable):
     """
 
     file_extension = Unicode(
-        'txt', config=True,
+        '.txt', config=True,
         help="Extension of the file that should be written to disk"
         )
 
diff --git a/IPython/nbconvert/exporters/html.py b/IPython/nbconvert/exporters/html.py
index 3df3810..d833691 100644
--- a/IPython/nbconvert/exporters/html.py
+++ b/IPython/nbconvert/exporters/html.py
@@ -32,7 +32,7 @@ class HTMLExporter(TemplateExporter):
     """
     
     def _file_extension_default(self):
-        return 'html'
+        return '.html'
 
     def _default_template_path_default(self):
         return os.path.join("..", "templates", "html")
diff --git a/IPython/nbconvert/exporters/latex.py b/IPython/nbconvert/exporters/latex.py
index 13015c3..779a8cc 100644
--- a/IPython/nbconvert/exporters/latex.py
+++ b/IPython/nbconvert/exporters/latex.py
@@ -37,7 +37,7 @@ class LatexExporter(TemplateExporter):
     """
 
     def _file_extension_default(self):
-        return 'tex'
+        return '.tex'
 
     def _template_file_default(self):
         return 'article'
diff --git a/IPython/nbconvert/exporters/pdf.py b/IPython/nbconvert/exporters/pdf.py
index 0ef2b2d..d79610b 100644
--- a/IPython/nbconvert/exporters/pdf.py
+++ b/IPython/nbconvert/exporters/pdf.py
@@ -135,7 +135,7 @@ class PDFExporter(LatexExporter):
         
         # convert output extension to pdf
         # the writer above required it to be tex
-        resources['output_extension'] = 'pdf'
+        resources['output_extension'] = '.pdf'
         
         return pdf_data, resources
     
diff --git a/IPython/nbconvert/exporters/python.py b/IPython/nbconvert/exporters/python.py
index 5c7dbf4..e1218da 100644
--- a/IPython/nbconvert/exporters/python.py
+++ b/IPython/nbconvert/exporters/python.py
@@ -23,7 +23,7 @@ class PythonExporter(TemplateExporter):
     Exports a Python code file.
     """
     def _file_extension_default(self):
-        return 'py'
+        return '.py'
 
     def _template_file_default(self):
         return 'python'
diff --git a/IPython/nbconvert/exporters/rst.py b/IPython/nbconvert/exporters/rst.py
index eaae267..731e978 100644
--- a/IPython/nbconvert/exporters/rst.py
+++ b/IPython/nbconvert/exporters/rst.py
@@ -26,7 +26,7 @@ class RSTExporter(TemplateExporter):
     """
     
     def _file_extension_default(self):
-        return 'rst'
+        return '.rst'
 
     def _template_file_default(self):
         return 'rst'
diff --git a/IPython/nbconvert/exporters/script.py b/IPython/nbconvert/exporters/script.py
new file mode 100644
index 0000000..2e1148a
--- /dev/null
+++ b/IPython/nbconvert/exporters/script.py
@@ -0,0 +1,14 @@
+"""Generic script exporter class for any kernel language"""
+
+from .templateexporter import TemplateExporter
+
+class ScriptExporter(TemplateExporter):
+    def _template_file_default(self):
+        return 'script'
+
+    def from_notebook_node(self, nb, resources=None, **kw):
+        langinfo = nb.metadata.get('language_info', {})
+        self.file_extension = langinfo.get('file_extension', '.txt')
+        self.output_mimetype = langinfo.get('mimetype', 'text/plain')
+
+        return super(ScriptExporter, self).from_notebook_node(nb, resources, **kw)
diff --git a/IPython/nbconvert/exporters/slides.py b/IPython/nbconvert/exporters/slides.py
index 8f4545e..fa84248 100644
--- a/IPython/nbconvert/exporters/slides.py
+++ b/IPython/nbconvert/exporters/slides.py
@@ -25,7 +25,7 @@ class SlidesExporter(HTMLExporter):
     """Exports HTML slides with reveal.js"""
     
     def _file_extension_default(self):
-        return 'slides.html'
+        return '.slides.html'
 
     def _template_file_default(self):
         return 'slides_reveal'
diff --git a/IPython/nbconvert/nbconvertapp.py b/IPython/nbconvert/nbconvertapp.py
index 1e252d0..115b645 100755
--- a/IPython/nbconvert/nbconvertapp.py
+++ b/IPython/nbconvert/nbconvertapp.py
@@ -286,7 +286,7 @@ class NbConvertApp(BaseIPythonApplication):
                 # strip duplicate extension from output_base, to avoid Basname.ext.ext
                 if getattr(exporter, 'file_extension', False):
                     base, ext = os.path.splitext(self.output_base)
-                    if ext == '.' + exporter.file_extension:
+                    if ext == exporter.file_extension:
                         self.output_base = base
                 notebook_name = self.output_base
             resources = {}
diff --git a/IPython/nbconvert/templates/script.tpl b/IPython/nbconvert/templates/script.tpl
new file mode 100644
index 0000000..cbd971d
--- /dev/null
+++ b/IPython/nbconvert/templates/script.tpl
@@ -0,0 +1,5 @@
+{%- extends 'null.tpl' -%}
+
+{% block input %}
+{{ cell.source }}
+{% endblock input %}
diff --git a/IPython/nbconvert/writers/files.py b/IPython/nbconvert/writers/files.py
index 01062e2..d124fb9 100644
--- a/IPython/nbconvert/writers/files.py
+++ b/IPython/nbconvert/writers/files.py
@@ -93,7 +93,7 @@ class FilesWriter(WriterBase):
 
             # Determine where to write conversion results.
             if output_extension is not None:
-                dest = notebook_name + '.' + output_extension
+                dest = notebook_name + output_extension
             else:
                 dest = notebook_name
             if self.build_directory:
diff --git a/IPython/nbconvert/writers/tests/test_files.py b/IPython/nbconvert/writers/tests/test_files.py
index a859a85..38793d1 100644
--- a/IPython/nbconvert/writers/tests/test_files.py
+++ b/IPython/nbconvert/writers/tests/test_files.py
@@ -59,7 +59,7 @@ class Testfiles(TestsBase):
         with self.create_temp_cwd():
 
             # Create the resoruces dictionary
-            res = {'output_extension': 'txt'}
+            res = {'output_extension': '.txt'}
 
             # Create files writer, test output
             writer = FilesWriter()
diff --git a/docs/source/development/messaging.rst b/docs/source/development/messaging.rst
index 625834c..47befeb 100644
--- a/docs/source/development/messaging.rst
+++ b/docs/source/development/messaging.rst
@@ -735,6 +735,9 @@ Message type: ``kernel_info_reply``::
         'language_info': {
             'mimetype': str,
 
+            # Extension without the dot, e.g. 'py'
+            'file_extension': str,
+
             # Pygments lexer, for highlighting
             # Only needed if it differs from the top level 'language' field.
             'pygments_lexer': str,
@@ -742,6 +745,11 @@ Message type: ``kernel_info_reply``::
             # Codemirror mode, for for highlighting in the notebook.
             # Only needed if it differs from the top level 'language' field.
             'codemirror_mode': str or dict,
+
+            # Nbconvert exporter, if notebooks written with this kernel should
+            # be exported with something other than the general 'script'
+            # exporter.
+            'nbconvert_exporter': str,
         },
 
         # A banner of information about the kernel,
diff --git a/docs/source/development/wrapperkernels.rst b/docs/source/development/wrapperkernels.rst
index 271c5da..4525150 100644
--- a/docs/source/development/wrapperkernels.rst
+++ b/docs/source/development/wrapperkernels.rst
@@ -38,9 +38,10 @@ following methods and attributes:
 
      Language information for :ref:`msging_kernel_info` replies, in a dictionary.
      This should contain the key ``mimetype`` with the mimetype of code in the
-     target language (e.g. ``'text/x-python'``). It may also contain keys
-     ``codemirror_mode`` and ``pygments_lexer`` if they need to differ from
-     :attr:`language`.
+     target language (e.g. ``'text/x-python'``), and ``file_extension`` (e.g.
+     ``'py'``).
+     It may also contain keys ``codemirror_mode`` and ``pygments_lexer`` if they
+     need to differ from :attr:`language`.
 
      Other keys may be added to this later.