diff --git a/src/calibre/ebooks/oeb/polish/parsing.py b/src/calibre/ebooks/oeb/polish/parsing.py
new file mode 100644
index 0000000000..3377931c73
--- /dev/null
+++ b/src/calibre/ebooks/oeb/polish/parsing.py
@@ -0,0 +1,199 @@
+#!/usr/bin/env python
+# vim:fileencoding=utf-8
+from __future__ import (unicode_literals, division, absolute_import,
+                        print_function)
+
+__license__ = 'GPL v3'
+__copyright__ = '2013, Kovid Goyal <kovid at kovidgoyal.net>'
+
+import copy
+
+from lxml.etree import ElementBase, XMLParser, ElementDefaultClassLookup, CommentBase
+
+from html5lib.constants import namespaces
+from html5lib.treebuilders._base import TreeBuilder as BaseTreeBuilder
+from html5lib.ihatexml import InfosetFilter
+
+infoset_filter = InfosetFilter()
+coerce_comment = infoset_filter.coerceComment
+coerce_text = infoset_filter.coerceCharacters
+
+def create_lxml_context():
+    parser = XMLParser()
+    parser.set_element_class_lookup(ElementDefaultClassLookup(element=Element, comment=Comment))
+    return parser
+
+def ElementFactory(name, namespace=None, context=None):
+    context = context or create_lxml_context()
+    ns = namespace or namespaces['html']
+    return context.makeelement('{%s}%s' % (ns, name), nsmap={None:ns})
+
+def CommentFactory(text):
+    return Comment(coerce_comment(text))
+
+class Element(ElementBase):
+
+    ''' Implements the interface required by the html5lib tree builders (see
+    html5lib.treebuilders._base.Node) on top of the lxml ElementBase class '''
+
+    def __str__(self):
+        attrs = ''
+        if self.attrib:
+            attrs = ' ' + ' '.join('%s="%s"' % (k, v) for k, v in self.attrib.iteritems())
+        ns = self.tag.rpartition('}')[0][1:]
+        prefix = {v:k for k, v in self.nsmap.iteritems()}[ns] or ''
+        if prefix:
+            prefix += ':'
+        return '<%s%s%s (%s)>' % (prefix, self.name, attrs, hex(id(self)))
+    __repr__ = __str__
+
+    @dynamic_property
+    def name(self):
+        def fget(self):
+            return self.tag.rpartition('}')[2]
+        def fset(self, val):
+            self.tag = '%s}%s' % (self.tag.rpartition('}')[2], val)
+        return property(fget=fget, fset=fset)
+
+    @property
+    def namespace(self):
+        return self.nsmap[self.prefix]
+
+    @dynamic_property
+    def attributes(self):
+        def fget(self):
+            return self.attrib
+        def fset(self, val):
+            attrs = {('{%s}%s' % k) if isinstance(k, tuple) else k : v for k, v in val.iteritems()}
+            self.attrib.clear()
+            self.attrib.update(attrs)
+        return property(fget=fget, fset=fset)
+
+    @dynamic_property
+    def childNodes(self):
+        def fget(self):
+            return self
+        def fset(self, val):
+            self[:] = list(val)
+        return property(fget=fget, fset=fset)
+
+    @property
+    def parent(self):
+        return self.getparent()
+
+    def hasContent(self):
+        return bool(self.text or len(self))
+
+    appendChild = ElementBase.append
+    removeChild = ElementBase.remove
+
+    def cloneNode(self):
+        return self.makeelement(self.tag, nsmap=self.nsmap, attrib=self.attrib)
+
+    def insertBefore(self, node, ref_node):
+        self.insert(self.index(ref_node), node)
+
+    def insertText(self, data, insertBefore=None):
+        data = coerce_text(data)
+        if len(self) == 0:
+            self.text = (self.text or '') + data
+        elif insertBefore is None:
+            # Insert the text as the tail of the last child element
+            el = self[-1]
+            el.tail = (el.tail or '') + data
+        else:
+            # Insert the text before the specified node
+            index = self.index(insertBefore)
+            if index > 0:
+                el = self[index - 1]
+                el.tail = (el.tail or '') + data
+            else:
+                self.text = (self.text or '') + data
+
+    def reparentChildren(self, new_parent):
+        # Move self.text
+        if len(new_parent) > 0:
+            el = new_parent[-1]
+            el.tail = (el.tail or '') + self.text
+        else:
+            if self.text:
+                new_parent.text = (new_parent.text or '') + self.text
+        self.text = None
+        for child in self:
+            new_parent.append(child)
+
+class Comment(CommentBase):
+
+    @dynamic_property
+    def data(self):
+        def fget(self):
+            return self.text
+        def fset(self, val):
+            self.text = coerce_comment(val)
+        return property(fget=fget, fset=fset)
+
+    @property
+    def parent(self):
+        return self.getparent()
+
+    @property
+    def name(self):
+        return None
+
+    @property
+    def namespace(self):
+        return None
+
+    @property
+    def childNodes(self):
+        return []
+
+    @property
+    def attributes(self):
+        return {}
+
+    def hasContent(self):
+        return bool(self.text)
+
+    def no_op(self, *args, **kwargs):
+        pass
+
+    appendChild = no_op
+    removeChild = no_op
+    insertBefore = no_op
+    reparentChildren = no_op
+
+    def insertText(self, text, insertBefore=None):
+        self.text = (self.text or '') + coerce_comment(text)
+
+    def cloneNode(self):
+        return copy.copy(self)
+
+class Document(object):
+
+    def __init__(self):
+        self.root = None
+        self.doctype = None
+
+    def appendChild(self, child):
+        if isinstance(child, Element):
+            self.root = child
+        elif isinstance(child, DocType):
+            self.doctype = child
+
+class DocType(object):
+
+    def __init__(self, name, public_id, system_id):
+        self.text = self.name = name
+        self.public_id, self.system_id = public_id, system_id
+
+class TreeBuilder(BaseTreeBuilder):
+
+    elementClass = ElementFactory
+    commentClass = Comment
+    documentClass = Document
+    doctypeClass = DocType
+
+    def __init__(self):
+        BaseTreeBuilder.__init__(self, True)
+