diff --git a/IPython/core/interactiveshell.py b/IPython/core/interactiveshell.py
index d987db3..8d5c743 100644
--- a/IPython/core/interactiveshell.py
+++ b/IPython/core/interactiveshell.py
@@ -1567,7 +1567,7 @@ class InteractiveShell(SingletonConfigurable):
         with self.builtin_trap:
             info = self._object_find(oname)
             if info.found:
-                return self.inspector._format_info(info.obj, oname, info=info,
+                return self.inspector._get_info(info.obj, oname, info=info,
                             detail_level=detail_level
                 )
             else:
diff --git a/IPython/core/oinspect.py b/IPython/core/oinspect.py
index ed4970c..118dc2c 100644
--- a/IPython/core/oinspect.py
+++ b/IPython/core/oinspect.py
@@ -112,7 +112,8 @@ def getdoc(obj):
 
     It also attempts to call a getdoc() method on the given object.  This
     allows objects which provide their docstrings via non-standard mechanisms
-    (like Pyro proxies) to still be inspected by ipython's ? system."""
+    (like Pyro proxies) to still be inspected by ipython's ? system.
+    """
     # Allow objects to offer customized documentation via a getdoc method:
     try:
         ds = obj.getdoc()
@@ -122,14 +123,13 @@ def getdoc(obj):
         # if we get extra info, we add it to the normal docstring.
         if isinstance(ds, string_types):
             return inspect.cleandoc(ds)
-    
     try:
         docstr = inspect.getdoc(obj)
         encoding = get_encoding(obj)
         return py3compat.cast_unicode(docstr, encoding=encoding)
     except Exception:
         # Harden against an inspect failure, which can occur with
-        # SWIG-wrapped extensions.
+        # extensions modules.
         raise
         return None
 
@@ -366,10 +366,11 @@ def find_source_lines(obj):
 
 
 class Inspector(Colorable):
+
     def __init__(self, color_table=InspectColors,
                  code_color_table=PyColorize.ANSICodeColors,
                  scheme='NoColor',
-                 str_detail_level=0, 
+                 str_detail_level=0,
                  parent=None, config=None):
         super(Inspector, self).__init__(parent=parent, config=config)
         self.color_table = color_table
@@ -430,7 +431,7 @@ class Inspector(Colorable):
 
     # In Python 3, all classes are new-style, so they all have __init__.
     @skip_doctest_py3
-    def pdoc(self,obj,oname='',formatter = None):
+    def pdoc(self, obj, oname='', formatter=None):
         """Print the docstring for any object.
 
         Optional:
@@ -505,7 +506,7 @@ class Inspector(Colorable):
 
     def pfile(self, obj, oname=''):
         """Show the whole file where an object was defined."""
-        
+
         lineno = find_source_lines(obj)
         if lineno is None:
             self.noinfo('file', oname)
@@ -541,96 +542,128 @@ class Inspector(Colorable):
             title_width = max(len(title) + 2 for title, _ in fields)
         for title, content in fields:
             if len(content.splitlines()) > 1:
-                title = header(title + ":") + "\n"
+                title = header(title + ':') + '\n'
             else:
-                title = header((title+":").ljust(title_width))
+                title = header((title + ':').ljust(title_width))
             out.append(cast_unicode(title) + cast_unicode(content))
         return "\n".join(out)
 
-    def _format_info(self, obj, oname='', formatter=None, info=None, detail_level=0):
-        """Format an info dict as text"""
+    def _mime_format(self, text, formatter=None):
+        """Return a mime bundle representation of the input text.
 
-        # hack docstring rendering
-        info = self.info(obj, oname=oname, formatter=None,
-                            info=info, detail_level=detail_level)
-        if formatter:
-            return formatter(info["docstring"])
-
-        displayfields = []
-        def add_fields(fields):
-            for title, key in fields:
-                field = info[key]
-                if field is not None:
-                    if key == "source":
-                        displayfields.append((title, self.format(cast_unicode(field.rstrip()))))
-                    else:
-                        displayfields.append((title, field.rstrip()))
+        - if `formatter` is None, the returned mime bundle has
+           a `text/plain` field, with the input text.
+           a `text/html` field with a `<pre>` tag containing the input text.
+
+        - if `formatter` is not None, it must be a callable transforming the
+          input text into a mime bundle. Default values for `text/plain` and
+          `text/html` representations are the ones described above.
+
+        Note:
+
+        Formatters returning strings are supported but this behavior is deprecated.
+
+        """
+        text = cast_unicode(text)
+        defaults = {
+            'text/plain': text,
+            'text/html': '<pre>' + text + '</pre>'
+        }
+
+        if formatter is None:
+            return defaults
+        else:
+            formatted = formatter(text)
+
+            if not isinstance(formatted, dict):
+                # Handle the deprecated behavior of a formatter returning
+                # a string instead of a mime bundle.
+                return {
+                    'text/plain': formatted,
+                    'text/html': '<pre>' + formatted + '</pre>'
+                }
+
+            else:
+                return dict(defaults, **formatted)
+
+    def _get_info(self, obj, oname='', formatter=None, info=None, detail_level=0):
+        """Retrieve an info dict and format it."""
+
+        info = self._info(obj, oname=oname, info=info, detail_level=detail_level)
+
+        mime = {
+            'text/plain': '',
+            'text/html': '',
+        }
+
+        def append_field(bundle, title, key, formatter=None):
+            field = info[key]
+            if field is not None:
+                formatted_field = self._mime_format(field, formatter)
+                bundle['text/plain'] += self.__head(title) + ':\n' + formatted_field['text/plain'] + '\n'
+                bundle['text/html'] += '<h1>' + title + '</h1>\n' + formatted_field['text/html'] + '\n'
+
+        def code_formatter(text):
+            return {
+                'text/plain': self.format(text),
+                'text/html': '<pre>' + text + '</pre>'
+            }
 
         if info['isalias']:
-            add_fields([('Repr', "string_form")])
+            append_field(mime, 'Repr', 'string_form')
 
         elif info['ismagic']:
-            if detail_level > 0 and info['source'] is not None:
-                add_fields([("Source", "source")])
+            if detail_level > 0:
+                append_field(mime, 'Source', 'source', code_formatter)
             else:
-                add_fields([("Docstring", "docstring")])
-
-            add_fields([("File", "file"),
-                       ])
+                append_field(mime, 'Docstring', 'docstring', formatter)
+            append_field(mime, 'File', 'file')
 
         elif info['isclass'] or is_simple_callable(obj):
             # Functions, methods, classes
-            add_fields([("Signature", "definition"),
-                        ("Init signature", "init_definition"),
-                       ])
-            if detail_level > 0 and info['source'] is not None:
-                add_fields([("Source", "source")])
+            append_field(mime, 'Signature', 'definition', code_formatter)
+            append_field(mime, 'Init signature', 'init_definition', code_formatter)
+            if detail_level > 0:
+                append_field(mime, 'Source', 'source', code_formatter)
             else:
-                add_fields([("Docstring", "docstring"),
-                            ("Init docstring", "init_docstring"),
-                           ])
+                append_field(mime, 'Docstring', 'docstring', formatter)
+                append_field(mime, 'Init docstring', 'init_docstring', formatter)
 
-            add_fields([('File', 'file'),
-                        ('Type', 'type_name'),
-                       ])
+            append_field(mime, 'File', 'file')
+            append_field(mime, 'Type', 'type_name')
 
         else:
             # General Python objects
-            add_fields([("Type", "type_name")])
+            append_field(mime, 'Type', 'type_name')
 
             # Base class for old-style instances
             if (not py3compat.PY3) and isinstance(obj, types.InstanceType) and info['base_class']:
-                displayfields.append(("Base Class", info['base_class'].rstrip()))
+                append_field(mime, 'Base Class', 'base_class')
 
-            add_fields([("String form", "string_form")])
+            append_field(mime, 'String form', 'string_form')
 
             # Namespace
             if info['namespace'] != 'Interactive':
-                displayfields.append(("Namespace", info['namespace'].rstrip()))
+                append_field(mime, 'Namespace', 'namespace')
 
-            add_fields([("Length", "length"),
-                        ("File", "file"),
-                        ("Signature", "definition"),
-                       ])
+            append_field(mime, 'Length', 'length')
+            append_field(mime, 'File', 'file'),
+            append_field(mime, 'Signature', 'definition', code_formatter)
 
             # Source or docstring, depending on detail level and whether
             # source found.
-            if detail_level > 0 and info['source'] is not None:
-                displayfields.append(("Source",
-                                      self.format(cast_unicode(info['source']))))
-            elif info['docstring'] is not None:
-                displayfields.append(("Docstring", info["docstring"]))
-
-            add_fields([("Class docstring", "class_docstring"),
-                        ("Init docstring", "init_docstring"),
-                        ("Call signature", "call_def"),
-                        ("Call docstring", "call_docstring")])
-        
-        if displayfields:
-            return self._format_fields(displayfields)
-        else:
-            return u''
-    
+            if detail_level > 0:
+                append_field(mime, 'Source', 'source', code_formatter)
+            else:
+                append_field(mime, 'Docstring', 'docstring', formatter)
+
+            append_field(mime, 'Class docstring', 'class_docstring', formatter)
+            append_field(mime, 'Init docstring', 'init_docstring', formatter)
+            append_field(mime, 'Call signature', 'call_def', code_formatter)
+            append_field(mime, 'Call docstring', 'call_docstring', formatter)
+
+        return mime
+
     def pinfo(self, obj, oname='', formatter=None, info=None, detail_level=0):
         """Show detailed information about an object.
 
@@ -638,26 +671,37 @@ class Inspector(Colorable):
 
         - oname: name of the variable pointing to the object.
 
-        - formatter: special formatter for docstrings (see pdoc)
+        - formatter: callable (optional)
+              A special formatter for docstrings.
+
+              The formatter is a callable that takes a string as an input
+              and returns either a formatted string or a mime type bundle
+              in the form of a dictionnary.
+
+              Although the support of custom formatter returning a string
+              instead of a mime type bundle is deprecated.
 
         - info: a structure with some information fields which may have been
           precomputed already.
 
         - detail_level: if set to 1, more information is given.
         """
-        text = self._format_info(obj, oname, formatter, info, detail_level)
-        if text:
-            page.page(text)
-    
+        info = self._get_info(obj, oname, formatter, info, detail_level)
+        if info:
+            page.page(info)
+
     def info(self, obj, oname='', formatter=None, info=None, detail_level=0):
+        """DEPRECATED. Compute a dict with detailed information about an object.
+        """
+        return self._info(obj, oname=oname, info=info, detail_level=detail_level)
+
+    def _info(self, obj, oname='', info=None, detail_level=0):
         """Compute a dict with detailed information about an object.
 
         Optional arguments:
 
         - oname: name of the variable pointing to the object.
 
-        - formatter: special formatter for docstrings (see pdoc)
-
         - info: a structure with some information fields which may have been
           precomputed already.
 
@@ -690,14 +734,12 @@ class Inspector(Colorable):
             ds = getdoc(obj)
             if ds is None:
                 ds = '<no docstring>'
-        if formatter is not None:
-            ds = formatter(ds)
 
         # store output in a dict, we initialize it here and fill it as we go
         out = dict(name=oname, found=True, isalias=isalias, ismagic=ismagic)
 
         string_max = 200 # max size of strings to show (snipped if longer)
-        shalf = int((string_max -5)/2)
+        shalf = int((string_max - 5) / 2)
 
         if ismagic:
             obj_type_name = 'Magic function'
@@ -798,7 +840,7 @@ class Inspector(Colorable):
             # reconstruct the function definition and print it:
             defln = self._getdef(obj, oname)
             if defln:
-                out['definition'] = self.format(defln)
+                out['definition'] = defln
 
             # First, check whether the instance docstring is identical to the
             # class one, and print it separately if they don't coincide.  In
@@ -832,7 +874,7 @@ class Inspector(Colorable):
             if safe_hasattr(obj, '__call__') and not is_simple_callable(obj):
                 call_def = self._getdef(obj.__call__, oname)
                 if call_def:
-                    call_def = self.format(call_def)
+                    call_def = call_def
                     # it may never be the case that call def and definition differ,
                     # but don't include the same signature twice
                     if call_def != out.get('definition'):
diff --git a/IPython/core/tests/test_oinspect.py b/IPython/core/tests/test_oinspect.py
index ed6c08a..f1d1bd6 100644
--- a/IPython/core/tests/test_oinspect.py
+++ b/IPython/core/tests/test_oinspect.py
@@ -340,13 +340,13 @@ if py3compat.PY3:
 @skipif(not py3compat.PY3)
 def test_definition_kwonlyargs():
     i = inspector.info(f_kwarg, oname='f_kwarg')  # analysis:ignore
-    nt.assert_equal(i['definition'], "f_kwarg(pos, *, kwonly)\n")
+    nt.assert_equal(i['definition'], "f_kwarg(pos, *, kwonly)")
 
 def test_getdoc():
     class A(object):
         """standard docstring"""
         pass
-    
+
     class B(object):
         """standard docstring"""
         def getdoc(self):