diff --git a/extension/latextext.py b/extension/latextext.py
index 4cc9aa5..6edb168 100755
--- a/extension/latextext.py
+++ b/extension/latextext.py
@@ -13,9 +13,10 @@
 from lxml import etree
 
 
-MAC = "Mac OS"
+MAC = "Darwin"
 WINDOWS = "Windows"
 PLATFORM = platform.system()
+PY3 = int(platform.python_version()[0]) >= 3
 
 STANDALONE = False
 LOG_LEVEL = 3
@@ -70,7 +71,7 @@ def log_message(msg_level, *msg):
         print(*msg)
     else:
         for m in msg:
-            inkex.debug(m)
+            inkex.utils.debug(m)
 
 
 def set_log_level(l):
@@ -95,9 +96,7 @@ class SvgTransformer:
 
     # matrix multiplication helper function
     def _matmult(self, a, b):
-        zip_b = zip(*b)
-        # uncomment next line if python 3 :
-        # zip_b = list(zip_b)
+        zip_b = list(zip(*b)) if PY3 else zip(*b)
         return [[sum(ele_a * ele_b for ele_a, ele_b in zip(row_a, col_b))
                  for col_b in zip_b] for row_a in a]
 
@@ -227,8 +226,8 @@ def __init__(self, infile, options):
         self.options = options
         self.svg_input = infile
 
-        self.defaults = dict2obj({"scale": 1.0, "depth": 0.0, "fontsize": 10, 
-                                  "preamble": "","packages": "amsmath,amssymb","math": False, 
+        self.defaults = dict2obj({"scale": 1.0, "depth": 0.0, "fontsize": 10,
+                                  "preamble": "","packages": "amsmath,amssymb","math": False,
                                   "newline": False})
 
         # load from file or use existing document root
@@ -469,7 +468,7 @@ def run(self):
             if txt_empty:
                 log_debug("Empty text element, skipping...")
                 continue
-            if self.options.math and latex_string[0] is not '$':
+            if self.options.math and latex_string[0] != '$':
                 latex_string = '$' + latex_string + '$'
             log_debug(latex_string)
             rendergroup = lat2svg.render(latex_string, self.options.preamble, self.options.packages, self.options.fontsize, self.options.scale)
@@ -587,8 +586,18 @@ def render(self, latex_code, preamble_file=None, package_list="", fontsize=10, s
         # Convert PDF to SVG
         if PLATFORM == WINDOWS:
             PDF2SVG_PATH = os.path.join(os.path.realpath(EXT_PATH), 'pdf2svg')
+        if PLATFORM == MAC:
+            if os.path.exists('/opt/local/bin/pdf2svg'):
+                PDF2SVG_PATH = '/opt/local/bin'
+            elif os.path.exists('/usr/local/bin/pdf2svg'):
+                PDF2SVG_PATH = '/usr/local/bin'
+            elif shutil.which("pdf2svg"):
+                PDF2SVG_PATH = os.path.dirname(shutil.which("pdf2svg"))
+            else:
+                log_error('PDF2SVG_PATH not found.')
         else:
             PDF2SVG_PATH = ''
+
         self._exec_command([os.path.join(PDF2SVG_PATH, 'pdf2svg'), os.path.join(tmp_path, 'tmp.pdf'), os.path.join(tmp_path, 'tmp.svg'), '1'])
 
         tree = etree.parse(os.path.join(tmp_path, 'tmp.svg'))
@@ -607,28 +616,23 @@ def render(self, latex_code, preamble_file=None, package_list="", fontsize=10, s
 # Init for standalone or Inkscape extension run mode
 
 # commandline options shared by standalone application and inkscape extension
-def add_options(parser):
-    parser.add_option("-o", "--outfile", dest="outfile",
-                      help="write to output file or directory", metavar="FILE")
-    parser.add_option("-p", "--preamble", dest="preamble",
-                      help="latex preamble file", metavar="FILE")
-    parser.add_option("-k", "--packages", dest="packages",
-                     help="comma separated list of additional latex packages to be loaded", metavar="LIST")
-    parser.add_option("-f", "--fontsize", dest="fontsize", type="int",
-                      help="latex base font size")
-    parser.add_option("-s", "--scale", dest="scale", type="float",
-                      help="apply additional scaling")
-    parser.add_option("-d", "--depth", dest="depth", type="int",
-                      help="maximum search depth for grouped text elements")
-    parser.add_option("-n", "--newline", dest="newline",
-                      action="store_true",
-                      help="insert \\\\ at every line break")
-    parser.add_option("-m", "--math", dest="math",
-                      action="store_true",
-                      help="encapsulate all text in math mode")
-    parser.add_option("-c", "--clean",
-                      action="store_true", dest="clean",
-                      help="remove all renderings")
+def add_arguments(parser):
+    parser.add_argument("-o", "--outfile", dest="outfile",
+                        help="write to output file or directory", metavar="FILE")
+    parser.add_argument("-p", "--preamble", dest="preamble",
+                        help="latex preamble file", metavar="FILE")
+    parser.add_argument("-k", "--packages", dest="packages",
+                        help="comma separated list of additional latex packages to be loaded",
+                        metavar="LIST")
+    parser.add_argument("-f", "--fontsize", dest="fontsize", type=int,
+                        help="latex base font size")
+    parser.add_argument("-s", "--scale", dest="scale", type=float,
+                        help="apply additional scaling")
+    parser.add_argument("-d", "--depth", dest="depth", type=int,
+                        help="maximum search depth for grouped text elements")
+    parser.add_argument("-c", "--clean",
+                        action="store_true", dest="clean",
+                        help="remove all renderings")
 
 
 if STANDALONE is False:
@@ -636,16 +640,15 @@ def add_options(parser):
     class RenderLatexEffect(inkex.Effect):
         def __init__(self):
             inkex.Effect.__init__(self)
-            add_options(self.OptionParser)
-            self.OptionParser.set_conflict_handler("resolve")
-            self.OptionParser.add_option("-l", "--log", type='inkbool',
-                                         action="store", dest="debug", default=False,
+            add_arguments(self.arg_parser)
+            self.arg_parser.add_argument("-l", "--log", type=inkex.utils.Boolean,
+                                         dest="debug", default=False,
                                          help="show log messages in inkscape")
-            self.OptionParser.add_option("-n", "--newline", dest="newline",
-                                         action="store", type='inkbool',
+            self.arg_parser.add_argument("-n", "--newline", dest="newline",
+                                         type=inkex.utils.Boolean,
                                          help="insert \newline at every line break")
-            self.OptionParser.add_option("-m", "--math", type='inkbool',
-                                         action="store", dest="math",
+            self.arg_parser.add_argument("-m", "--math", type=inkex.utils.Boolean,
+                                         dest="math",
                                          help="encapsulate all text in math mode")
 
         def effect(self):
@@ -657,39 +660,48 @@ def effect(self):
     # Create a standalone commandline application
     def main_standalone():
         # parse commandline arguments
-        from optparse import OptionParser
-        parser = OptionParser(usage="usage: %prog [options] SVGfile(s)")
-        add_options(parser)
-        parser.add_option("-v", "--verbose", default=False,
-                          action="store_true", dest="verbose")
-        (options, args) = parser.parse_args()
-
-        if options.verbose is True:
+        import argparse
+        parser = argparse.ArgumentParser(conflict_handler='resolve')
+        add_arguments(parser)
+        parser.add_argument("-n", "--newline", dest="newline",
+                            action="store_true",
+                            help="insert \\\\ at every line break")
+        parser.add_argument("-m", "--math", dest="math",
+                            action="store_true",
+                            help="encapsulate all text in math mode")
+        parser.add_argument("-v", "--verbose", default=False,
+                            action="store_true", dest="verbose")
+        parser.add_argument("svg", type=str, nargs='+',
+                            metavar="FILE",
+                            help="SVGfile(s)")
+        args = parser.parse_args()
+
+        if args.verbose is True:
             set_log_level(log_level_debug)
 
         # expand wildcards
-        args = [glob.glob(arg) if '*' in arg else arg for arg in args]
+        files = [glob.glob(arg) if '*' in arg else arg for arg in args.svg]
 
-        if len(args) < 1:
+        if len(files) < 1:
             log_error('No input file specified! Call with -h argument for usage instructions.')
             sys.exit(1)
-        elif len(args) > 2 and options.outfile and not os.path.isdir(options.outfile):
+        elif len(files) > 2 and args.outfile and not os.path.isdir(args.outfile):
             log_error('If more than one input file is specified -o/--outfile has to point to a directory.')
             sys.exit(1)
 
         # main loop, run the SVG processor for each input file
-        for infile in args:
-            if options.outfile:
-                if os.path.isdir(options.outfile):
-                    outfile = os.path.join(options.outfile, os.path.basename(infile))
+        for infile in files:
+            if args.outfile:
+                if os.path.isdir(args.outfile):
+                    outfile = os.path.join(args.outfile, os.path.basename(infile))
                 else:
-                    outfile = options.outfile
+                    outfile = args.outfile
             else:
                 outfile = infile
 
             log_info("Rendering " + infile + " -> " + outfile)
 
-            svgprocessor = SvgProcessor(infile, options)
+            svgprocessor = SvgProcessor(infile, args)
 
             try:
                 result = svgprocessor.run()
@@ -708,6 +720,6 @@ def main_standalone():
     if STANDALONE is False:
         # run the extension
         effect = RenderLatexEffect()
-        effect.affect()
+        effect.run()
     else:
         main_standalone()
diff --git a/extension/latextext_gtk3.inx b/extension/latextext_gtk3.inx
index 7a6763b..1bb5592 100644
--- a/extension/latextext_gtk3.inx
+++ b/extension/latextext_gtk3.inx
@@ -4,7 +4,6 @@
 	<id>org.inkscape.render.latextext_gtk3</id>
 	<dependency type="executable" location="extensions">latextext.py</dependency>
 	<dependency type="executable" location="extensions">latextext_gtk3.py</dependency>
-    <dependency type="executable" location="extensions">inkex.py</dependency>
 	<effect>
 		<object-type>all</object-type>
 		<effects-menu>
diff --git a/extension/latextext_gtk3.py b/extension/latextext_gtk3.py
index dfcb158..f772343 100755
--- a/extension/latextext_gtk3.py
+++ b/extension/latextext_gtk3.py
@@ -53,7 +53,7 @@ def prepare_dialog(self, options):
 
         row_count = 0
         box0 = Gtk.Box(spacing=6)
-        grid.attach(Gtk.Label("Preamble File"), 0, row_count, 1, 1)
+        grid.attach(Gtk.Label(label="Preamble File"), 0, row_count, 1, 1)
         self.entryPreamble = Gtk.Entry()
         self.entryPreamble.set_text(options.preamble)
         self.entryPreamble.set_hexpand(True)
@@ -65,14 +65,14 @@ def prepare_dialog(self, options):
         grid.attach(box0, 1, row_count, 1, 1)
 
         row_count += 1
-        grid.attach(Gtk.Label("Additional Packages"), 0, row_count, 1, 1)
+        grid.attach(Gtk.Label(label="Additional Packages"), 0, row_count, 1, 1)
         self.entryPackages = Gtk.Entry()
         self.entryPackages.set_text(options.packages)
         self.entryPackages.set_hexpand(True)
         grid.attach(self.entryPackages, 1, row_count, 1, 1)
 
         row_count += 1
-        grid.attach(Gtk.Label("Document base font size"), 0, row_count, 1, 1)
+        grid.attach(Gtk.Label(label="Document base font size"), 0, row_count, 1, 1)
         self.entryFontsize = Gtk.SpinButton.new_with_range(1, 32, 1)
         self.entryFontsize.set_value(options.fontsize)
         self.entryFontsize.set_hexpand(False)
@@ -82,29 +82,29 @@ def prepare_dialog(self, options):
         self.entryScale = Gtk.SpinButton.new_with_range(0.01, 20.0, 0.05)
         self.entryScale.set_digits(2)
         self.entryScale.set_value(options.scale)
-        grid.attach(Gtk.Label("Scale factor"), 0, row_count, 1, 1)
+        grid.attach(Gtk.Label(label="Scale factor"), 0, row_count, 1, 1)
         grid.attach(self.entryScale, 1, row_count, 1, 1)
 
         row_count += 1
         self.entryDepth = Gtk.SpinButton.new_with_range(0, 100, 1)
         self.entryDepth.set_value(options.depth)
-        grid.attach(Gtk.Label("SVG/XML tree max. depth"), 0, row_count, 1, 1)
+        grid.attach(Gtk.Label(label="SVG/XML tree max. depth"), 0, row_count, 1, 1)
         grid.attach(self.entryDepth, 1, row_count, 1, 1)
 
         row_count += 1
-        grid.attach(Gtk.Label("Add \\\\ at every line break"), 0, row_count, 1, 1)
+        grid.attach(Gtk.Label(label="Add \\\\ at every line break"), 0, row_count, 1, 1)
         self.btnNewline = Gtk.CheckButton()
         self.btnNewline.set_active(options.newline)
         grid.attach(self.btnNewline, 1, row_count, 1, 1)
 
         row_count += 1
-        grid.attach(Gtk.Label("Encapsulate all text with ($..$)"), 0, row_count, 1, 1)
+        grid.attach(Gtk.Label(label="Encapsulate all text with ($..$)"), 0, row_count, 1, 1)
         self.btnMath = Gtk.CheckButton()
         self.btnMath.set_active(options.math)
         grid.attach(self.btnMath, 1, row_count, 1, 1)
 
         row_count += 1
-        grid.attach(Gtk.Label("Show log messages"), 0, row_count, 1, 1)
+        grid.attach(Gtk.Label(label="Show log messages"), 0, row_count, 1, 1)
         self.btnShowLog = Gtk.CheckButton()
         grid.attach(self.btnShowLog, 1, row_count, 1, 1)
 
@@ -128,10 +128,11 @@ def prepare_dialog(self, options):
         self.set_default(btnApply)
 
     def on_select_preamble(self, widget):
-        dialog = Gtk.FileChooserDialog("Please choose a Latex preamble file", self,
+        dialog = Gtk.FileChooserDialog(self,
                                        Gtk.FileChooserAction.OPEN,
                                        (Gtk.STOCK_CANCEL, Gtk.ResponseType.CANCEL,
-                                        Gtk.STOCK_OPEN, Gtk.ResponseType.OK))
+                                        Gtk.STOCK_OPEN, Gtk.ResponseType.OK),
+                                       label="Please choose a Latex preamble file")
         dialog.set_keep_above(True)
         dialog.set_modal(True)
         response = dialog.run()
@@ -174,4 +175,4 @@ def effect(self):
 
 if __name__ == "__main__":
     effect = RenderLatexEffectGTK3()
-    effect.affect()
+    effect.run()