diff --git a/README.rst b/README.rst
index 0a66401..6d6e77c 100644
--- a/README.rst
+++ b/README.rst
@@ -66,6 +66,7 @@ Currently, following formats are supported:
 
 - lrf (for Sony readers)
 - epub
+- mobi
 
 
 Installation
diff --git a/ebook_converter/ebooks/mobi/mobiml.py b/ebook_converter/ebooks/mobi/mobiml.py
index 94c8114..93a2559 100644
--- a/ebook_converter/ebooks/mobi/mobiml.py
+++ b/ebook_converter/ebooks/mobi/mobiml.py
@@ -11,13 +11,13 @@ import copy
 import re
 import numbers
 from lxml import etree
-from calibre.ebooks.oeb.base import namespace, barename
-from calibre.ebooks.oeb.base import XHTML, XHTML_NS, urlnormalize
-from calibre.ebooks.oeb.stylizer import Stylizer
-from calibre.ebooks.oeb.transforms.flatcss import KeyMapper
-from calibre.ebooks.mobi.utils import convert_color_for_font_tag
-from calibre.utils.imghdr import identify
-from polyglot.builtins import unicode_type, string_or_bytes
+from ebook_converter.ebooks.oeb.base import namespace, barename
+from ebook_converter.ebooks.oeb.base import XHTML, XHTML_NS, urlnormalize
+from ebook_converter.ebooks.oeb.stylizer import Stylizer
+from ebook_converter.ebooks.oeb.transforms.flatcss import KeyMapper
+from ebook_converter.ebooks.mobi.utils import convert_color_for_font_tag
+from ebook_converter.utils.imghdr import identify
+from ebook_converter.polyglot.builtins import unicode_type, string_or_bytes
 
 MBP_NS = 'http://mobipocket.com/ns/mbp'
 
diff --git a/ebook_converter/ebooks/mobi/utils.py b/ebook_converter/ebooks/mobi/utils.py
index fab0632..7dd2943 100644
--- a/ebook_converter/ebooks/mobi/utils.py
+++ b/ebook_converter/ebooks/mobi/utils.py
@@ -175,9 +175,9 @@ def rescale_image(data, maxsizeb=IMAGE_MAX_SIZE, dimen=None):
         else:
             width = height = dimen
         data = scale_image(data, width=width, height=height, compression_quality=90)[-1]
-    else:
+    # else:
         # Replace transparent pixels with white pixels and convert to JPEG
-        data = save_cover_data_to(data)
+        #data = save_cover_data_to(data)
     if len(data) <= maxsizeb:
         return data
     orig_data = data  # save it in case compression fails
diff --git a/ebook_converter/ebooks/mobi/writer2/indexer.py b/ebook_converter/ebooks/mobi/writer2/indexer.py
index c5c9d81..6fd397a 100644
--- a/ebook_converter/ebooks/mobi/writer2/indexer.py
+++ b/ebook_converter/ebooks/mobi/writer2/indexer.py
@@ -11,9 +11,9 @@ from struct import pack
 import io
 from collections import OrderedDict, defaultdict
 
-from calibre.ebooks.mobi.utils import (encint, encode_number_as_hex,
+from ebook_converter.ebooks.mobi.utils import (encint, encode_number_as_hex,
         encode_tbs, align_block, RECORD_SIZE, CNCX as CNCX_)
-from polyglot.builtins import filter, iteritems, itervalues, map, range
+from ebook_converter.polyglot.builtins import filter, iteritems, itervalues, map, range
 
 
 class CNCX(CNCX_):  # {{{
diff --git a/ebook_converter/ebooks/mobi/writer2/main.py b/ebook_converter/ebooks/mobi/writer2/main.py
index 884628d..9d5b429 100644
--- a/ebook_converter/ebooks/mobi/writer2/main.py
+++ b/ebook_converter/ebooks/mobi/writer2/main.py
@@ -9,16 +9,16 @@ __docformat__ = 'restructuredtext en'
 import io, random, time
 from struct import pack
 
-from calibre.ebooks import normalize
-from calibre.ebooks.mobi.writer2.serializer import Serializer
-from calibre.ebooks.compression.palmdoc import compress_doc
-from calibre.ebooks.mobi.langcodes import iana2mobi
-from calibre.utils.filenames import ascii_filename
-from calibre.ebooks.mobi.writer2 import (PALMDOC, UNCOMPRESSED)
-from calibre.ebooks.mobi.utils import (encint, encode_trailing_data,
+from ebook_converter.ebooks import normalize
+from ebook_converter.ebooks.mobi.writer2.serializer import Serializer
+from ebook_converter.ebooks.compression.palmdoc import compress_doc
+from ebook_converter.ebooks.mobi.langcodes import iana2mobi
+from ebook_converter.utils.filenames import ascii_filename
+from ebook_converter.ebooks.mobi.writer2 import (PALMDOC, UNCOMPRESSED)
+from ebook_converter.ebooks.mobi.utils import (encint, encode_trailing_data,
         align_block, detect_periodical, RECORD_SIZE, create_text_record)
-from calibre.ebooks.mobi.writer2.indexer import Indexer
-from polyglot.builtins import iteritems, unicode_type, range
+from ebook_converter.ebooks.mobi.writer2.indexer import Indexer
+from ebook_converter.polyglot.builtins import iteritems, unicode_type, range
 
 # Disabled as I dont care about uncrossable breaks
 WRITE_UNCROSSABLE_BREAKS = False
@@ -201,7 +201,7 @@ class MobiWriter(object):
                 # header as well
                 bt = 0x103 if self.indexer.is_flat_periodical else 0x101
 
-        from calibre.ebooks.mobi.writer8.exth import build_exth
+        from ebook_converter.ebooks.mobi.writer8.exth import build_exth
         exth = build_exth(metadata,
                 prefer_author_sort=self.opts.prefer_author_sort,
                 is_periodical=self.is_periodical,
@@ -374,9 +374,9 @@ class MobiWriter(object):
     # }}}
 
     def generate_joint_record0(self):  # {{{
-        from calibre.ebooks.mobi.writer8.mobi import (MOBIHeader,
+        from ebook_converter.ebooks.mobi.writer8.mobi import (MOBIHeader,
                 HEADER_FIELDS)
-        from calibre.ebooks.mobi.writer8.exth import build_exth
+        from ebook_converter.ebooks.mobi.writer8.exth import build_exth
 
         # Insert resource records
         first_image_record = None
diff --git a/ebook_converter/ebooks/mobi/writer2/resources.py b/ebook_converter/ebooks/mobi/writer2/resources.py
index 90b70ac..c569a1f 100644
--- a/ebook_converter/ebooks/mobi/writer2/resources.py
+++ b/ebook_converter/ebooks/mobi/writer2/resources.py
@@ -46,8 +46,14 @@ class Resources(object):
         try:
             return func(data)
         except Exception:
-            if 'png' != what(None, data):
+            ext = what(None, data)
+            if ext not in ('png', 'gif'):
                 raise
+            if ext == 'gif':
+                with PersistentTemporaryFile(suffix='.gif') as pt:
+                    pt.write(data)
+                    return mobify_image(data)
+
             with PersistentTemporaryFile(suffix='.png') as pt:
                 pt.write(data)
             try:
diff --git a/ebook_converter/ebooks/mobi/writer2/serializer.py b/ebook_converter/ebooks/mobi/writer2/serializer.py
index 756d2d7..f78ca5d 100644
--- a/ebook_converter/ebooks/mobi/writer2/serializer.py
+++ b/ebook_converter/ebooks/mobi/writer2/serializer.py
@@ -12,13 +12,13 @@ import unicodedata
 from collections import defaultdict
 from io import BytesIO
 
-from calibre.ebooks.mobi.mobiml import MBP_NS
-from calibre.ebooks.mobi.utils import is_guide_ref_start
-from calibre.ebooks.oeb.base import (
+from ebook_converter.ebooks.mobi.mobiml import MBP_NS
+from ebook_converter.ebooks.mobi.utils import is_guide_ref_start
+from ebook_converter.ebooks.oeb.base import (
     OEB_DOCS, XHTML, XHTML_NS, XML_NS, namespace, prefixname, urlnormalize
 )
-from polyglot.builtins import unicode_type, string_or_bytes
-from polyglot.urllib import urldefrag
+from ebook_converter.polyglot.builtins import unicode_type, string_or_bytes
+from ebook_converter.polyglot.urllib import urldefrag
 
 
 class Buf(BytesIO):
diff --git a/ebook_converter/ebooks/mobi/writer8/__init__.py b/ebook_converter/ebooks/mobi/writer8/__init__.py
index 357137f..e69de29 100644
--- a/ebook_converter/ebooks/mobi/writer8/__init__.py
+++ b/ebook_converter/ebooks/mobi/writer8/__init__.py
@@ -1,10 +0,0 @@
-#!/usr/bin/env python2
-# vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
-from __future__ import absolute_import, division, print_function, unicode_literals
-
-__license__   = 'GPL v3'
-__copyright__ = '2012, Kovid Goyal <kovid@kovidgoyal.net>'
-__docformat__ = 'restructuredtext en'
-
-
-
diff --git a/ebook_converter/ebooks/mobi/writer8/cleanup.py b/ebook_converter/ebooks/mobi/writer8/cleanup.py
index 9483eea..bd3a00d 100644
--- a/ebook_converter/ebooks/mobi/writer8/cleanup.py
+++ b/ebook_converter/ebooks/mobi/writer8/cleanup.py
@@ -6,7 +6,7 @@ __license__   = 'GPL v3'
 __copyright__ = '2012, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
-from calibre.ebooks.oeb.base import XPath
+from ebook_converter.ebooks.oeb.base import XPath
 
 
 class CSSCleanup(object):
diff --git a/ebook_converter/ebooks/mobi/writer8/exth.py b/ebook_converter/ebooks/mobi/writer8/exth.py
index d997b3a..110475b 100644
--- a/ebook_converter/ebooks/mobi/writer8/exth.py
+++ b/ebook_converter/ebooks/mobi/writer8/exth.py
@@ -10,11 +10,11 @@ import re
 from struct import pack
 from io import BytesIO
 
-from calibre.constants import iswindows, isosx
-from calibre.ebooks.mobi.utils import (utf8_text, to_base)
-from calibre.utils.localization import lang_as_iso639_1
-from calibre.ebooks.metadata import authors_to_sort_string
-from polyglot.builtins import iteritems, unicode_type
+from ebook_converter.constants import iswindows, isosx
+from ebook_converter.ebooks.mobi.utils import (utf8_text, to_base)
+from ebook_converter.utils.localization import lang_as_iso639_1
+from ebook_converter.ebooks.metadata import authors_to_sort_string
+from ebook_converter.polyglot.builtins import iteritems, unicode_type
 
 EXTH_CODES = {
     'creator': 100,
@@ -99,7 +99,7 @@ def build_exth(metadata, prefer_author_sort=False, is_periodical=False,
 
     # Write UUID as ASIN
     uuid = None
-    from calibre.ebooks.oeb.base import OPF
+    from ebook_converter.ebooks.oeb.base import OPF
     for x in metadata['identifier']:
         if (x.get(OPF('scheme'), None).lower() == 'uuid' or
                 unicode_type(x).startswith('urn:uuid:')):
diff --git a/ebook_converter/ebooks/oeb/transforms/htmltoc.py b/ebook_converter/ebooks/oeb/transforms/htmltoc.py
index df6f699..50bd876 100644
--- a/ebook_converter/ebooks/oeb/transforms/htmltoc.py
+++ b/ebook_converter/ebooks/oeb/transforms/htmltoc.py
@@ -6,10 +6,10 @@ HTML-TOC-adding transform.
 __license__   = 'GPL v3'
 __copyright__ = '2008, Marshall T. Vandegrift <llasram@gmail.com>'
 
-from calibre.ebooks.oeb.base import XML, XHTML, XHTML_NS
-from calibre.ebooks.oeb.base import XHTML_MIME, CSS_MIME
-from calibre.ebooks.oeb.base import element, XPath
-from polyglot.builtins import unicode_type
+from ebook_converter.ebooks.oeb.base import XML, XHTML, XHTML_NS
+from ebook_converter.ebooks.oeb.base import XHTML_MIME, CSS_MIME
+from ebook_converter.ebooks.oeb.base import element, XPath
+from ebook_converter.polyglot.builtins import unicode_type
 
 __all__ = ['HTMLTOCAdder']
 
@@ -69,7 +69,7 @@ class HTMLTOCAdder(object):
 
         if 'toc' in oeb.guide:
             # Ensure toc pointed to in <guide> is in spine
-            from calibre.ebooks.oeb.base import urlnormalize
+            from ebook_converter.ebooks.oeb.base import urlnormalize
             href = urlnormalize(oeb.guide['toc'].href)
             if href in oeb.manifest.hrefs:
                 item = oeb.manifest.hrefs[href]
diff --git a/ebook_converter/ebooks/oeb/transforms/manglecase.py b/ebook_converter/ebooks/oeb/transforms/manglecase.py
index 24c1a9a..b2caaa6 100644
--- a/ebook_converter/ebooks/oeb/transforms/manglecase.py
+++ b/ebook_converter/ebooks/oeb/transforms/manglecase.py
@@ -7,11 +7,11 @@ __license__   = 'GPL v3'
 __copyright__ = '2008, Marshall T. Vandegrift <llasram@gmail.com>'
 
 from lxml import etree
-from calibre.ebooks.oeb.base import XHTML, XHTML_NS
-from calibre.ebooks.oeb.base import CSS_MIME
-from calibre.ebooks.oeb.base import namespace
-from calibre.ebooks.oeb.stylizer import Stylizer
-from polyglot.builtins import string_or_bytes
+from ebook_converter.ebooks.oeb.base import XHTML, XHTML_NS
+from ebook_converter.ebooks.oeb.base import CSS_MIME
+from ebook_converter.ebooks.oeb.base import namespace
+from ebook_converter.ebooks.oeb.stylizer import Stylizer
+from ebook_converter.polyglot.builtins import string_or_bytes
 
 CASE_MANGLER_CSS = """
 .calibre_lowercase {
diff --git a/ebook_converter/ebooks/oeb/transforms/rasterize.py b/ebook_converter/ebooks/oeb/transforms/rasterize.py
index 0a58dc6..246cc34 100644
--- a/ebook_converter/ebooks/oeb/transforms/rasterize.py
+++ b/ebook_converter/ebooks/oeb/transforms/rasterize.py
@@ -8,17 +8,17 @@ __copyright__ = '2008, Marshall T. Vandegrift <llasram@gmail.com>'
 
 import os, re
 
-from PyQt5.Qt import (
-    Qt, QByteArray, QBuffer, QIODevice, QColor, QImage, QPainter, QSvgRenderer)
-from calibre.ebooks.oeb.base import XHTML, XLINK
-from calibre.ebooks.oeb.base import SVG_MIME, PNG_MIME
-from calibre.ebooks.oeb.base import xml2str, xpath
-from calibre.ebooks.oeb.base import urlnormalize
-from calibre.ebooks.oeb.stylizer import Stylizer
-from calibre.ptempfile import PersistentTemporaryFile
-from calibre.utils.imghdr import what
-from polyglot.builtins import unicode_type
-from polyglot.urllib import urldefrag
+# from PyQt5.Qt import (
+    # Qt, QByteArray, QBuffer, QIODevice, QColor, QImage, QPainter, QSvgRenderer)
+from ebook_converter.ebooks.oeb.base import XHTML, XLINK
+from ebook_converter.ebooks.oeb.base import SVG_MIME, PNG_MIME
+from ebook_converter.ebooks.oeb.base import xml2str, xpath
+from ebook_converter.ebooks.oeb.base import urlnormalize
+from ebook_converter.ebooks.oeb.stylizer import Stylizer
+from ebook_converter.ptempfile import PersistentTemporaryFile
+from ebook_converter.utils.imghdr import what
+from ebook_converter.polyglot.builtins import unicode_type
+from ebook_converter.polyglot.urllib import urldefrag
 
 IMAGE_TAGS = {XHTML('img'), XHTML('object')}
 KEEP_ATTRS = {'class', 'style', 'width', 'height', 'align'}
@@ -32,8 +32,8 @@ class SVGRasterizer(object):
 
     def __init__(self, base_css=''):
         self.base_css = base_css
-        from calibre.gui2 import must_use_qt
-        must_use_qt()
+        # from ebook_converter.gui2 import must_use_qt
+        # must_use_qt()
 
     @classmethod
     def config(cls, cfg):
diff --git a/ebook_converter/ebooks/pdf/__init__.py b/ebook_converter/ebooks/pdf/__init__.py
index c23e175..e69de29 100644
--- a/ebook_converter/ebooks/pdf/__init__.py
+++ b/ebook_converter/ebooks/pdf/__init__.py
@@ -1,10 +0,0 @@
-#!/usr/bin/env  python2
-from __future__ import absolute_import, division, print_function, unicode_literals
-
-__license__   = 'GPL v3'
-__copyright__ = '2008, Kovid Goyal kovid@kovidgoyal.net'
-__docformat__ = 'restructuredtext en'
-
-'''
-Used for pdf output for comic2pdf
-'''
diff --git a/ebook_converter/ebooks/pdf/pdftohtml.py b/ebook_converter/ebooks/pdf/pdftohtml.py
index 9df116b..248e37c 100644
--- a/ebook_converter/ebooks/pdf/pdftohtml.py
+++ b/ebook_converter/ebooks/pdf/pdftohtml.py
@@ -11,15 +11,15 @@ import shutil
 import subprocess
 import sys
 
-from calibre import CurrentDir, xml_replace_entities, prints
-from calibre.constants import (
+from ebook_converter import CurrentDir, xml_replace_entities, prints
+from ebook_converter.constants import (
     filesystem_encoding, isbsd, islinux, isosx, ispy3, iswindows
 )
-from calibre.ebooks import ConversionError, DRMError
-from calibre.ebooks.chardet import xml_to_unicode
-from calibre.ptempfile import PersistentTemporaryFile
-from calibre.utils.cleantext import clean_xml_chars
-from calibre.utils.ipc import eintr_retry_call
+from ebook_converter.ebooks import ConversionError, DRMError
+from ebook_converter.ebooks.chardet import xml_to_unicode
+from ebook_converter.ptempfile import PersistentTemporaryFile
+from ebook_converter.utils.cleantext import clean_xml_chars
+from ebook_converter.utils.ipc import eintr_retry_call
 
 
 PDFTOHTML = 'pdftohtml'
@@ -98,7 +98,7 @@ def pdftohtml(output_dir, pdf_path, no_images, as_xml=False):
             with lopen(index, 'r+b') as i:
                 raw = i.read().decode('utf-8', 'replace')
                 raw = flip_images(raw)
-                raw = raw.replace('<head', '<!-- created by calibre\'s pdftohtml -->\n  <head', 1)
+                raw = raw.replace('<head', '<!-- created by ebook_converter\'s pdftohtml -->\n  <head', 1)
                 i.seek(0)
                 i.truncate()
                 # versions of pdftohtml >= 0.20 output self closing <br> tags, this
@@ -129,11 +129,11 @@ def pdftohtml(output_dir, pdf_path, no_images, as_xml=False):
 
 def parse_outline(raw, output_dir):
     from lxml import etree
-    from calibre.utils.xml_parse import safe_xml_fromstring
+    from ebook_converter.utils.xml_parse import safe_xml_fromstring
     raw = clean_xml_chars(xml_to_unicode(raw, strip_encoding_pats=True, assume_utf8=True)[0])
     outline = safe_xml_fromstring(raw).xpath('(//outline)[1]')
     if outline:
-        from calibre.ebooks.oeb.polish.toc import TOC, create_ncx
+        from ebook_converter.ebooks.oeb.polish.toc import TOC, create_ncx
         outline = outline[0]
         toc = TOC()
         count = [0]
@@ -156,7 +156,7 @@ def parse_outline(raw, output_dir):
 
 
 def flip_image(img, flip):
-    from calibre.utils.img import flip_image, image_and_format_from_data, image_to_data
+    from ebook_converter.utils.img import flip_image, image_and_format_from_data, image_to_data
     with lopen(img, 'r+b') as f:
         img, fmt = image_and_format_from_data(f.read())
         img = flip_image(img, horizontal='x' in flip, vertical='y' in flip)