diff --git a/.gitignore b/.gitignore
index af3cbac..f0d6df7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,7 @@
 .cache
+.eggs
+.tox/
 dist/
 ffmpeg/tests/sample_data/dummy2.mp4
-venv
+ffmpeg_python.egg-info/
+venv*
diff --git a/.python-version b/.python-version
new file mode 100644
index 0000000..e2d8f77
--- /dev/null
+++ b/.python-version
@@ -0,0 +1,5 @@
+3.3.6
+3.4.6
+3.5.3
+3.6.1
+jython-2.7.0
diff --git a/.travis.yml b/.travis.yml
index 4442bf1..f1863cd 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,9 +1,36 @@
 language: python
 before_install:
-  - curl -O https://johnvansickle.com/ffmpeg/releases/ffmpeg-3.3.1-64bit-static.tar.xz
-  - tar Jxf ffmpeg-3.3.1-64bit-static.tar.xz
+  - >
+    [ -f ffmpeg-3.3.1-64bit-static/ffmpeg ] || (
+        curl -O https://johnvansickle.com/ffmpeg/releases/ffmpeg-3.3.1-64bit-static.tar.xz &&
+        tar Jxf ffmpeg-3.3.1-64bit-static.tar.xz
+    )
+matrix:
+  include:
+    - python: 2.7
+      env:
+      - TOX_ENV=py27
+    - python: 3.3
+      env:
+      - TOX_ENV=py33
+    - python: 3.4
+      env:
+      - TOX_ENV=py34
+    - python: 3.5
+      env:
+      - TOX_ENV=py35
+    - python: 3.6
+      env:
+      - TOX_ENV=py36
+    - python: pypy
+      env:
+      - TOX_ENV=pypy
 install:
-  - pip install -r requirements.txt
+  - pip install tox
 script:
   - export PATH=$(readlink -f ffmpeg-3.3.1-64bit-static):$PATH
-  - py.test
+  - tox -e $TOX_ENV
+cache:
+  directories:
+    - .tox
+    - ffmpeg-3.3.1-64bit-static
diff --git a/ffmpeg/__init__.py b/ffmpeg/__init__.py
index ff5c064..1953609 100644
--- a/ffmpeg/__init__.py
+++ b/ffmpeg/__init__.py
@@ -1,3 +1,4 @@
+from __future__ import unicode_literals
 from . import _filters, _ffmpeg, _run
 from ._filters import *
 from ._ffmpeg import *
diff --git a/ffmpeg/_ffmpeg.py b/ffmpeg/_ffmpeg.py
index c9c7f19..0d0a549 100644
--- a/ffmpeg/_ffmpeg.py
+++ b/ffmpeg/_ffmpeg.py
@@ -1,3 +1,4 @@
+from __future__ import unicode_literals
 from .nodes import (
     FilterNode,
     GlobalNode,
diff --git a/ffmpeg/_filters.py b/ffmpeg/_filters.py
index 9794e2c..6329648 100644
--- a/ffmpeg/_filters.py
+++ b/ffmpeg/_filters.py
@@ -1,3 +1,4 @@
+from __future__ import unicode_literals
 from .nodes import (
     FilterNode,
     operator,
diff --git a/ffmpeg/_run.py b/ffmpeg/_run.py
index 28a3e46..d57b286 100644
--- a/ffmpeg/_run.py
+++ b/ffmpeg/_run.py
@@ -1,3 +1,6 @@
+from __future__ import unicode_literals
+
+from past.builtins import basestring
 import operator as _operator
 import subprocess as _subprocess
 
@@ -13,6 +16,7 @@ from .nodes import (
     operator,
     OutputNode,
 )
+from functools import reduce
 
 def _get_stream_name(name):
     return '[{}]'.format(name)
diff --git a/ffmpeg/nodes.py b/ffmpeg/nodes.py
index 61c9ff0..c6359e2 100644
--- a/ffmpeg/nodes.py
+++ b/ffmpeg/nodes.py
@@ -1,3 +1,6 @@
+from __future__ import unicode_literals
+
+from builtins import object
 import hashlib
 import json
 
@@ -18,15 +21,18 @@ class Node(object):
         formatted_props += ['{}={!r}'.format(key, self._kwargs[key]) for key in sorted(self._kwargs)]
         return '{}({})'.format(self._name, ','.join(formatted_props))
 
+    def __hash__(self):
+        return int(self._hash, base=16)
+
     def __eq__(self, other):
         return self._hash == other._hash
 
     def _update_hash(self):
         props = {'args': self._args, 'kwargs': self._kwargs}
-        my_hash = hashlib.md5(json.dumps(props, sort_keys=True)).hexdigest()
+        my_hash = hashlib.md5(json.dumps(props, sort_keys=True).encode('utf-8')).hexdigest()
         parent_hashes = [parent._hash for parent in self._parents]
         hashes = parent_hashes + [my_hash]
-        self._hash = hashlib.md5(','.join(hashes)).hexdigest()
+        self._hash = hashlib.md5(','.join(hashes).encode('utf-8')).hexdigest()
 
 
 class InputNode(Node):
diff --git a/ffmpeg/tests/test_ffmpeg.py b/ffmpeg/tests/test_ffmpeg.py
index 7e38521..b8e983d 100644
--- a/ffmpeg/tests/test_ffmpeg.py
+++ b/ffmpeg/tests/test_ffmpeg.py
@@ -1,4 +1,4 @@
-from ffmpeg.nodes import operator, FilterNode
+from __future__ import unicode_literals
 import ffmpeg
 import os
 import pytest
@@ -72,12 +72,12 @@ def test_repr():
     trim3 = ffmpeg.trim(in_file, start_frame=50, end_frame=60)
     concatted = ffmpeg.concat(trim1, trim2, trim3)
     output = ffmpeg.output(concatted, 'dummy2.mp4')
-    assert repr(in_file) == "input(filename='dummy.mp4')"
+    assert repr(in_file) == "input(filename={!r})".format('dummy.mp4')
     assert repr(trim1) == "trim(end_frame=20,start_frame=10)"
     assert repr(trim2) == "trim(end_frame=40,start_frame=30)"
     assert repr(trim3) == "trim(end_frame=60,start_frame=50)"
     assert repr(concatted) == "concat(n=3)"
-    assert repr(output) == "output(filename='dummy2.mp4')"
+    assert repr(output) == "output(filename={!r})".format('dummy2.mp4')
 
 
 def test_get_args_simple():
diff --git a/requirements.txt b/requirements.txt
index 55ff9de..b5e8ae3 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,5 @@
+future
 pytest
+pytest-runner
 sphinx
+tox
diff --git a/setup.cfg b/setup.cfg
new file mode 100644
index 0000000..b7e4789
--- /dev/null
+++ b/setup.cfg
@@ -0,0 +1,2 @@
+[aliases]
+test=pytest
diff --git a/setup.py b/setup.py
index d8b6334..0e11dab 100644
--- a/setup.py
+++ b/setup.py
@@ -1,5 +1,4 @@
-from distutils.core import setup
-from ffmpeg._filters import __all__ as filter_names
+from setuptools import setup
 from textwrap import dedent
 import subprocess
 
@@ -61,18 +60,34 @@ misc_keywords = [
     'wrapper',
 ]
 
-keywords = misc_keywords + file_formats + filter_names
+keywords = misc_keywords + file_formats
 
 setup(
-    name = 'ffmpeg-python',
-    packages = ['ffmpeg'],
-    version = '0.1.5',
-    description = 'Python bindings for FFmpeg - with support for complex filtering',
-    author = 'Karl Kroening',
-    author_email = 'karlk@kralnet.us',
-    url = 'https://github.com/kkroening/ffmpeg-python',
-    download_url = download_url,
-    classifiers = [],
-    keywords = keywords,
-    long_description = long_description,
+    name='ffmpeg-python',
+    packages=['ffmpeg'],
+    setup_requires=['pytest-runner'],
+    tests_require=['pytest'],
+    version='0.1.5',
+    description='Python bindings for FFmpeg - with support for complex filtering',
+    author='Karl Kroening',
+    author_email='karlk@kralnet.us',
+    url='https://github.com/kkroening/ffmpeg-python',
+    download_url=download_url,
+    keywords=keywords,
+    long_description=long_description,
+    install_requires=['future'],
+    classifiers=[
+        'Intended Audience :: Developers',
+        'License :: OSI Approved :: Apache Software License',
+        'Natural Language :: English',
+        'Operating System :: OS Independent',
+        'Programming Language :: Python',
+        'Programming Language :: Python :: 2',
+        'Programming Language :: Python :: 2.7',
+        'Programming Language :: Python :: 3',
+        'Programming Language :: Python :: 3.3',
+        'Programming Language :: Python :: 3.4',
+        'Programming Language :: Python :: 3.5',
+        'Programming Language :: Python :: 3.6',
+    ],
 )
diff --git a/tox.ini b/tox.ini
new file mode 100644
index 0000000..ed5c2e6
--- /dev/null
+++ b/tox.ini
@@ -0,0 +1,13 @@
+# Tox (https://tox.readthedocs.io/) is a tool for running tests
+# in multiple virtualenvs. This configuration file will run the
+# test suite on all supported python versions. To use it, "pip install tox"
+# and then run "tox" from this directory.
+
+[tox]
+envlist = py27, py33, py34, py35, py36, pypy
+
+[testenv]
+commands = py.test
+deps =
+    future
+    pytest