diff --git a/Documentation/doc/CMakeLists.txt b/Documentation/doc/CMakeLists.txt
index 5ff79cbed2c..e069d2eb4e8 100644
--- a/Documentation/doc/CMakeLists.txt
+++ b/Documentation/doc/CMakeLists.txt
@@ -27,7 +27,7 @@ else()
 endif()
 
 find_package(Doxygen)
-find_package(PythonInterp)
+find_package(Python3 COMPONENTS Interpreter)
 
 if(NOT DOXYGEN_FOUND)
   message(WARNING "Cannot build the documentation without Doxygen!")
@@ -322,9 +322,9 @@ endif()
 set(CGAL_DOC_VERSION ${CGAL_CREATED_VERSION_NUM})
 
 ## generate how_to_cite files
-if(PYTHONINTERP_FOUND)
+if(Python3_Interpreter_FOUND)
   execute_process(
-    COMMAND ${PYTHON_EXECUTABLE} ${CGAL_DOC_SCRIPT_DIR}/generate_how_to_cite.py
+    COMMAND ${Python3_EXECUTABLE} ${CGAL_DOC_SCRIPT_DIR}/generate_how_to_cite.py
             ${CGAL_ROOT} ${CMAKE_BINARY_DIR} "${CGAL_BRANCH_BUILD}"
     RESULT_VARIABLE GENERATE_HOW_TO_CITE_RESULT)
   if(NOT GENERATE_HOW_TO_CITE_RESULT EQUAL "0")
@@ -436,25 +436,25 @@ add_dependencies(Documentation_copy_doc_tags doc_pre)
 #total level doc dependencies
 add_dependencies(doc doc_post)
 
-if(PYTHONINTERP_FOUND)
+if(Python3_Interpreter_FOUND)
   set(CGAL_DOC_TESTSUITE_SCRIPT "${CGAL_DOC_SCRIPT_DIR}/testsuite.py")
 
   add_custom_target(
     doc_with_postprocessing
-    ${PYTHON_EXECUTABLE} ${CGAL_DOC_SCRIPT_DIR}/html_output_post_processing.py
+    ${Python3_EXECUTABLE} ${CGAL_DOC_SCRIPT_DIR}/html_output_post_processing.py
     --output ${CGAL_DOC_OUTPUT_DIR} --resources ${CGAL_DOC_RESOURCE_DIR})
   add_dependencies(doc_with_postprocessing doc)
 
   if(CGAL_DOC_CREATE_LOGS)
     add_custom_target(
       Documentation_test
-      ${PYTHON_EXECUTABLE} ${CGAL_DOC_TESTSUITE_SCRIPT} --output-dir
+      ${Python3_EXECUTABLE} ${CGAL_DOC_TESTSUITE_SCRIPT} --output-dir
       ${CGAL_DOC_OUTPUT_DIR} --doc-log-dir ${CGAL_DOC_LOG_DIR})
     add_dependencies(Documentation_test doc)
 
     add_custom_target(
       Documentation_test_publish
-      ${PYTHON_EXECUTABLE}
+      ${Python3_EXECUTABLE}
       ${CGAL_DOC_TESTSUITE_SCRIPT}
       --output-dir
       ${CGAL_DOC_OUTPUT_DIR}
@@ -467,7 +467,7 @@ if(PYTHONINTERP_FOUND)
 
     add_custom_target(
       doc_and_publish_testsuite
-      ${PYTHON_EXECUTABLE}
+      ${Python3_EXECUTABLE}
       ${CGAL_DOC_TESTSUITE_SCRIPT}
       --output-dir
       ${CGAL_DOC_OUTPUT_DIR}
diff --git a/Documentation/doc/scripts/documentation_parser.py b/Documentation/doc/scripts/documentation_parser.py
index 462291efae6..ce117b098db 100644
--- a/Documentation/doc/scripts/documentation_parser.py
+++ b/Documentation/doc/scripts/documentation_parser.py
@@ -4,6 +4,7 @@ from pyquery import PyQuery as pq
 from collections import defaultdict
 from sys import argv 
 import os.path as op
+import codecs
 
 # if _in is part of args, return true.
 def check_type(_in, args):
@@ -33,7 +34,8 @@ for i in range(0,len(compounds)):
       filepath='class'+compound+'.xml'
       total_path=op.join(op.sep, root_path,filepath)
       if(op.isfile(total_path)):
-        e = pq(filename=total_path, parser="xml")
+        file_content = codecs.open(total_path, 'rb')
+        e = pq(file_content.read(), parser="xml")
         compoundnames=[p.text() for p in list(e('includes').items())]
         
         if(len(compoundnames) > 1 and compoundnames[0].find("Concept") != -1):
diff --git a/Documentation/doc/scripts/generate_how_to_cite.py b/Documentation/doc/scripts/generate_how_to_cite.py
index 0f02a1a8500..e1108d6a51f 100644
--- a/Documentation/doc/scripts/generate_how_to_cite.py
+++ b/Documentation/doc/scripts/generate_how_to_cite.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # coding: utf8
 
 import re
@@ -157,7 +157,7 @@ def protect_upper_case(title):
   return title.replace("dD","{dD}").replace("2D","{2D}").replace("3D","{3D}").replace("CGAL","{CGAL}").replace("Qt","{Qt}").replace("Boost","{Boost}")
 
 def protect_accentuated_letters(authors):
-  res=authors.replace(u"é",r"{\'e}").replace(u"è",r"{\`e}").replace(u"É",r"{\'E}").replace(u"ä",r"{\"a}").replace(u"ö",r"{\"o}").replace(u"ñ",r"{\~n}").replace(u"ã",r"{\~a}").replace(u"ë",r"{\"e}").replace(u"ı",r"{\i}").replace(u"Ş",r"{\c{S}}").replace(u"ş",r"{\c{s}}").replace("%","")
+  res=authors.replace("é",r"{\'e}").replace("è",r"{\`e}").replace("É",r"{\'E}").replace("ä",r"{\"a}").replace("ö",r"{\"o}").replace("ñ",r"{\~n}").replace("ã",r"{\~a}").replace("ë",r"{\"e}").replace("ı",r"{\i}").replace("Ş",r"{\c{S}}").replace("ş",r"{\c{s}}").replace("%","")
   try:
     res.encode('ascii')
   except UnicodeEncodeError:
diff --git a/Documentation/doc/scripts/html_output_post_processing.py b/Documentation/doc/scripts/html_output_post_processing.py
index f963ac29744..f01a02f1eef 100755
--- a/Documentation/doc/scripts/html_output_post_processing.py
+++ b/Documentation/doc/scripts/html_output_post_processing.py
@@ -56,13 +56,14 @@ def write_out_html(d, fn):
     # this is the normal doxygen doctype, which is thrown away by pyquery
     f.write('<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "https://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">\n')
     f.write('<html xmlns=\"http://www.w3.org/1999/xhtml\">')
-    f.write(d.html())
+    if d.html() is not None:
+      f.write(d.html())
     f.write('\n')
     f.write('</html>\n')
     f.close()
 
 def package_glob(target):
-    return filter(lambda x: not os.path.join(os.path.join('.','Manual'),'')  in x, glob.glob(target))
+    return [x for x in glob.glob(target) if not os.path.join(os.path.join('.','Manual'),'')  in x]
 
 # remove duplicate files
 def clean_doc():
@@ -127,7 +128,8 @@ def re_replace_first_in_file(pat, s_after, fname):
 def is_concept_file(filename):
   if not path.exists(filename):
     return False;
-  d = pq(filename=filename, parser='html', encoding='utf-8')
+  file_content = codecs.open(filename, 'r', encoding='utf-8')
+  d = pq(file_content.read(),parser="html")
   ident = d('#CGALConcept')
   return ident.size() == 1
 
@@ -190,7 +192,8 @@ def automagically_number_figures():
     return
 
 
-  d = pq(filename="./Manual/packages.html", parser='html', encoding='utf-8')
+  file_content = codecs.open("./Manual/packages.html", 'r', encoding='utf-8')
+  d = pq(file_content.read(),parser="html")
   for el in d('a.elRef'):
     text = pq(el).attr('href')
     if text.find("index.html")!=-1:
@@ -210,14 +213,16 @@ def automagically_number_figures():
     all_pkg_files.remove(userman)
     for fname in [userman]+all_pkg_files:
       infos=figure_anchor_info(pkg_id, global_anchor_map)
-      d = pq(filename=fname, parser='html', encoding='utf-8')
+      file_content = codecs.open(fname, 'r', encoding='utf-8')
+      d = pq(file_content.read(), parser="html")
       d('a.anchor').each( lambda i: collect_figure_anchors(i,infos) )
     pkg_id+=1
 
   #Figure link dev Manual
   for fname in glob.glob("Manual/*.html"):
     infos=figure_anchor_info(0, global_anchor_map)
-    d = pq(filename=fname, parser='html', encoding='utf-8')
+    file_content = codecs.open(fname, 'r', encoding='utf-8')
+    d = pq(file_content.read(),parser="html")
     d('a.anchor').each( lambda i: collect_figure_anchors(i,infos) )
 
   #replace each link to a figure by its unique id
@@ -227,7 +232,8 @@ def automagically_number_figures():
     with codecs.open(fname, encoding='utf-8') as f:
         if not any(re.search("fig__", line) for line in f):
             continue # pattern does not occur in file so we are done.
-    d = pq(filename=fname, parser='html', encoding='utf-8')
+    file_content = codecs.open(fname, 'r', encoding='utf-8')
+    d = pq(file_content.read(), parser="html")
     d('a.el').each( lambda i: update_figure_ref(i,global_anchor_map) )
     d('a.elRef').each( lambda i: update_figure_ref(i,global_anchor_map) )
     write_out_html(d, fname)
@@ -261,7 +267,8 @@ removes some unneeded files, and performs minor repair on some glitches.''')
       re_replace_in_file("<span class=\"icon\">N</span>", "<span class=\"icon-namespace\">N</span>", fn)
       re_replace_in_file("<span class=\"icon\">C</span>", "<span class=\"icon-class\">C</span>", fn)
       dir_name=path.dirname(fn)
-      d = pq(filename=fn, parser='html', encoding='utf-8')
+      file_content = codecs.open(fn, 'r', encoding='utf-8')
+      d = pq(file_content.read(), parser="html")
       tr_tags = d('table.directory tr img')
       tr_tags.each(lambda i: rearrange_img(i, dir_name))
       span_tags = d('table.directory tr span')
@@ -270,7 +277,8 @@ removes some unneeded files, and performs minor repair on some glitches.''')
     class_files=list(package_glob('./*/class*.html'))
     class_files.extend(package_glob('./*/struct*.html'))
     for fn in class_files:
-        d = pq(filename=fn, parser='html', encoding='utf-8')
+        file_content = codecs.open(fn, 'r', encoding='utf-8')
+        d = pq(file_content.read(), parser="html")
         ident = d('#CGALConcept')
         if ident.size() == 1:
             conceptify(d);
@@ -284,7 +292,8 @@ removes some unneeded files, and performs minor repair on some glitches.''')
 
     namespace_files=package_glob('./*/namespace*.html')
     for fn in namespace_files:
-        d = pq(filename=fn, parser='html', encoding='utf-8')
+        file_content = codecs.open(fn, 'r', encoding='utf-8')
+        d = pq(file_content.read(), parser="html")
         ident = d('#CGALConceptNS')
         if ident.size() == 1:
             conceptify_ns(d);
@@ -294,14 +303,16 @@ removes some unneeded files, and performs minor repair on some glitches.''')
     # in a group we only need to change the nested-classes
     group_files=package_glob('./*/group*Concepts*.html')
     for fn in group_files:
-        d = pq(filename=fn, parser='html',encoding='utf-8')
+        file_content = codecs.open(fn, 'r', encoding='utf-8')
+        d = pq(file_content.read(), parser="html")
         conceptify_nested_classes(d)
         write_out_html(d, fn)
 
     # fix up Files
     files_files=package_glob('./*/files.html')
     for fn in files_files:
-        d = pq(filename=fn, parser='html',encoding='utf-8')
+        file_content = codecs.open(fn, 'r', encoding='utf-8')
+        d = pq(file_content.read(), parser="html")
         table = d("table.directory")
         row_id=table("td.entry").filter(lambda i: pq(this).text() == 'Concepts').parent().attr('id')
         if row_id != None:
@@ -331,7 +342,8 @@ removes some unneeded files, and performs minor repair on some glitches.''')
     relationship_pages.extend(package_glob('./*/generalizes.html'))
     relationship_pages.extend(package_glob('./*/refines.html'))
     for fn in relationship_pages:
-        d = pq(filename=fn, parser='html',encoding='utf-8')
+        file_content = codecs.open(fn, 'r', encoding='utf-8')
+        d = pq(file_content.read(), parser="html")
         dts=d(".textblock .reflist dt")
         # no contents() on pyquery, do it the hard way
         # Note that in the following regular expression, the Struct did not appear in doxygen version 1.8.3
@@ -343,7 +355,8 @@ removes some unneeded files, and performs minor repair on some glitches.''')
     # throw out nav-sync
     all_pages=glob.glob('./*/*.html')
     for fn in all_pages:
-        d = pq(filename=fn, parser='html',encoding='utf-8')
+        file_content = codecs.open(fn, 'r', encoding='utf-8')
+        d = pq(file_content.read(), parser="html")
         d('#nav-sync').hide()
         # TODO count figures
         write_out_html(d, fn)
@@ -366,7 +379,8 @@ removes some unneeded files, and performs minor repair on some glitches.''')
     # remove class name in Definition section if there is no default template
     # parameter documented
     for fn in class_and_struct_files:
-        d = pq(filename=fn, parser='html',encoding='utf-8')
+        file_content = codecs.open(fn, 'r', encoding='utf-8')
+        d = pq(file_content.read(), parser="html")
         for el in d('h3'):
           text = pq(el).text()
           if text[0:9]=="template<" and text.find('=')==-1:
diff --git a/Documentation/doc/scripts/process_doc.sh b/Documentation/doc/scripts/process_doc.sh
index a447df9cae9..a41940ee2fd 100644
--- a/Documentation/doc/scripts/process_doc.sh
+++ b/Documentation/doc/scripts/process_doc.sh
@@ -53,7 +53,11 @@ PATH_TO_MASTER="$PWD/doxygen_master/build/bin/doxygen"
 echo "done."
 
 echo "comparing versions 1.8.4 and 1.8.13"
-bash -$- test_doxygen_versions.sh $PATH_TO_1_8_4 $PATH_TO_1_8_13 $PWD/doc_1_8_4 $PWD/doc_1_8_13 $PUBLISH_DIR
+bash -$- test_doxygen_versions.sh $PATH_TO_1_8_4 $PATH_TO_1_8_13 $PWD/doc_1_8_4 $PWD/doc_1_8_13  $PUBLISH_DIR
+if [ ! -d $PWD/doc_1_8_13/doc_log ]; then
+  echo "NO DOC LOGS."
+  exit 1
+fi
 mv diff.txt diff1.txt
 
 echo "comparing versions 1.8.4 and master"
@@ -70,13 +74,13 @@ fi
 #update overview
 CGAL_NAME=$(cat cgal_version)
 if [ "$DO_COMPARE" = "TRUE" ]; then
-  python ${PWD}/testsuite.py --output-dir1 $PWD/doc_1_8_4/doc_output/ --output-dir2 $PWD/doc_1_8_13/doc_output/ --doc-log-dir1 $PWD/doc_1_8_4/doc_log/ \
+  python3 ${PWD}/testsuite.py --output-dir1 $PWD/doc_1_8_4/doc_output/ --output-dir2 $PWD/doc_1_8_13/doc_output/ --doc-log-dir1 $PWD/doc_1_8_4/doc_log/ \
     --doc-log-dir2 $PWD/doc_1_8_13/doc_log/ --doc-log-dir-master $PWD/doc_master/doc_log/ \
     --publish $PUBLISH_DIR --diff1 $PWD/diff1.txt --diff2 $PWD/diff2.txt --master-dir $PWD/doc_master/doc_output/ \
     --cgal-version "$CGAL_NAME" --do-copy-results --version-to-keep 10 --doxygen-version1 "$DOXYGEN_1" --doxygen-version2 "$DOXYGEN_2" --master-describe "$MASTER_DESCRIBE"
 else
   echo "NO MASTER"
-  python ${PWD}/testsuite.py --output-dir1 $PWD/doc_1_8_4/doc_output/ --output-dir2 $PWD/doc_1_8_13/doc_output/ --doc-log-dir1 $PWD/doc_1_8_4/doc_log/ \
+  python3 ${PWD}/testsuite.py --output-dir1 $PWD/doc_1_8_4/doc_output/ --output-dir2 $PWD/doc_1_8_13/doc_output/ --doc-log-dir1 $PWD/doc_1_8_4/doc_log/ \
     --doc-log-dir2 $PWD/doc_1_8_13/doc_log/ --doc-log-dir-master $PWD/doc_master/ \
     --publish $PUBLISH_DIR --diff1 $PWD/diff1.txt \
     --cgal-version "$CGAL_NAME" --do-copy-results --version-to-keep 10 --doxygen-version1 "$DOXYGEN_1" --doxygen-version2 "$DOXYGEN_2"
diff --git a/Documentation/doc/scripts/testsuite.py b/Documentation/doc/scripts/testsuite.py
index efaa0f31f0c..89819f1e591 100755
--- a/Documentation/doc/scripts/testsuite.py
+++ b/Documentation/doc/scripts/testsuite.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright (c) 2012 GeometryFactory (France). All rights reserved.
 # All rights reserved.
 # 
@@ -88,7 +88,7 @@ body  {color: black; background-color: #C0C0D0; font-family: sans-serif;}
 <th>Errors</th>
 </tr>
 </table></body></html>'''
-    
+
     if args.publish and args.do_copy_results:
       suffix=''
       if args.doxygen_version1:
@@ -97,7 +97,7 @@ body  {color: black; background-color: #C0C0D0; font-family: sans-serif;}
       suffix = ''
       if args.doxygen_version2:
         suffix = args.doxygen_version2
-      link2="\n<br><a href=\"output2/Manual/index.html\">Documentation built</a> with <a href=\"https://github.com/CGAL/doxygen\">our fork of Doxygen {_suffix} (used for the official CGAL documentation)</a>\n".format(_suffix=suffix)
+      link2="\n<br><a href=\"output2/Manual/index.html\">Documentation built</a> with <a href=\"https://github.com/CGAL/doxygen\">our fork of Doxygen {_suffix} (used for the official CGAL documentation)</a>\n".format(_suffix=suffix) 
       suffix = ''
       if args.master_describe:
         suffix=args.master_describe
diff --git a/Scripts/developer_scripts/run_doxygen_testsuite b/Scripts/developer_scripts/run_doxygen_testsuite
index 62e1a5d2eeb..a796d4dfde5 100755
--- a/Scripts/developer_scripts/run_doxygen_testsuite
+++ b/Scripts/developer_scripts/run_doxygen_testsuite
@@ -58,8 +58,6 @@ if [ ! -d "${CGAL_DOC_BUILD}/${CGAL_RELEASE_ID}" ]; then
 fi
 cd "${CGAL_RELEASE_ID}"
 
-PYTHONPATH=/home/cgal-testsuite/.local/lib/python2.6/site-packages
-export PYTHONPATH
 PATH=/home/cgal-testsuite/local/bin:$PATH
 export PATH
 cd "$PWD/doc/scripts"