diff --git a/.coveragerc b/.coveragerc
new file mode 100644
index 0000000..af40312
--- /dev/null
+++ b/.coveragerc
@@ -0,0 +1,6 @@
+[run]
+source = src
+
+[report]
+exclude_lines =
+    pragma: no cover
diff --git a/.gitignore b/.gitignore
index 5149542..6bacfe5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,3 +9,5 @@ build/
 dist/
 *.egg-info/
 .tox/
+.coverage
+htmlcov/
diff --git a/.travis.yml b/.travis.yml
index 02dca11..dc7e4b8 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,9 +1,20 @@
 language: python
+sudo: false
 python:
     - 2.7
+    - pypy-5.4.1
+    - 3.5
+    - 3.6
 install:
-    - pip install .
+    - pip install -U pip setuptools
+    - pip install -U coverage coveralls
+    - pip install -U -e .[test]
 script:
-    - python setup.py test -q
+  - coverage run -m zope.testrunner --test-path=src  --auto-color --auto-progress
 notifications:
     email: false
+after_success:
+    - coveralls
+cache: pip
+before_cache:
+    - rm -f $HOME/.cache/pip/log/debug.log
diff --git a/CHANGES.txt b/CHANGES.rst
similarity index 81%
rename from CHANGES.txt
rename to CHANGES.rst
index ad26321..3a52fd6 100644
--- a/CHANGES.txt
+++ b/CHANGES.rst
@@ -2,9 +2,13 @@
 CHANGES
 =======
 
-3.5.2 (unreleased)
+4.0.0 (unreleased)
 ------------------
 
+- Add support for Python 3.5 and 3.6 and PyPy.
+
+- Removed support for Python 2.6.
+
 - Added `tox.ini` and manifest.
 
 - Removed zope.app.testing dependency.
diff --git a/MANIFEST.in b/MANIFEST.in
index 61dad0f..de58807 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -2,7 +2,7 @@ include *.rst
 include *.txt
 include tox.ini
 include bootstrap.py
-include buildout.cfg
+include *.cfg
 
 recursive-include src *
 
diff --git a/README.txt b/README.rst
similarity index 100%
rename from README.txt
rename to README.rst
diff --git a/setup.cfg b/setup.cfg
new file mode 100644
index 0000000..2a9acf1
--- /dev/null
+++ b/setup.cfg
@@ -0,0 +1,2 @@
+[bdist_wheel]
+universal = 1
diff --git a/setup.py b/setup.py
index ed8a981..3bff94b 100644
--- a/setup.py
+++ b/setup.py
@@ -17,55 +17,70 @@
 # Zope Toolkit policies as described by this documentation.
 ##############################################################################
 """Setup for zope.app.dependable package
-
-$Id$
 """
 import os
 from setuptools import setup, find_packages
 
 def read(*rnames):
-    return open(os.path.join(os.path.dirname(__file__), *rnames)).read()
+    with open(os.path.join(os.path.dirname(__file__), *rnames)) as f:
+        return f.read()
+
+version = '4.0.0.dev0'
+tests_require = [
+    'zope.container',
+    'zope.testing',
+    'zope.testrunner',
+]
 
 setup(name='zope.app.dependable',
-      version = '3.5.2dev',
+      version=version,
       author='Zope Corporation and Contributors',
       author_email='zope-dev@zope.org',
       description='Simple Dependency API',
       long_description=(
-          read('README.txt')
+          read('README.rst')
           + '\n\n' +
-          read('CHANGES.txt')
+          read('CHANGES.rst')
           ),
-      keywords = "zope3 dependency",
-      classifiers = [
+      keywords="zope3 dependency",
+      classifiers=[
           'Development Status :: 5 - Production/Stable',
           'Environment :: Web Environment',
           'Intended Audience :: Developers',
           'License :: OSI Approved :: Zope Public License',
           'Programming Language :: Python',
           'Programming Language :: Python :: 2',
-          'Programming Language :: Python :: 2.6',
           'Programming Language :: Python :: 2.7',
+          'Programming Language :: Python :: 3',
+          'Programming Language :: Python :: 3.5',
+          'Programming Language :: Python :: 3.6',
           'Programming Language :: Python :: Implementation :: CPython',
+          'Programming Language :: Python :: Implementation :: PyPy',
           'Natural Language :: English',
           'Operating System :: OS Independent',
           'Topic :: Internet :: WWW/HTTP',
-          'Framework :: Zope3'],
-      url='http://pypi.python.org/pypi/zope.app.dependable',
+          'Framework :: Zope3',
+      ],
+      url='http://github.com/zopefoundation/zope.app.dependable',
       license='ZPL 2.1',
       packages=find_packages('src'),
-      package_dir = {'': 'src'},
+      package_dir={'': 'src'},
       namespace_packages=['zope', 'zope.app'],
-      extras_require=dict(test=[]),
-      install_requires=['setuptools',
-                        'zope.annotation',
-                        'zope.exceptions',
-                        'zope.i18nmessageid',
-                        'zope.interface',
-                        'zope.lifecycleevent',
-                        'zope.location',
-                        'zope.traversing',
-                        ],
-      include_package_data = True,
-      zip_safe = False,
+      extras_require={
+          'test': tests_require,
+      },
+      tests_require=tests_require,
+      install_requires=[
+          'setuptools',
+          'zope.annotation',
+          'zope.exceptions',
+          'zope.i18nmessageid',
+          'zope.interface',
+          'zope.lifecycleevent',
+          'zope.location',
+          'zope.traversing',
+      ],
+      include_package_data=True,
+      zip_safe=False,
+      test_suite='zope.app.dependable.tests',
       )
diff --git a/src/zope/__init__.py b/src/zope/__init__.py
index bf99a9d..155a31d 100644
--- a/src/zope/__init__.py
+++ b/src/zope/__init__.py
@@ -1,8 +1,2 @@
 # this is a namespace package
-try:
-    import pkg_resources
-    pkg_resources.declare_namespace(__name__)
-except ImportError:
-    import pkgutil
-    __path__ = pkgutil.extend_path(__path__, __name__)
-
+__import__('pkg_resources').declare_namespace(__name__) # pragma: no cover
diff --git a/src/zope/app/__init__.py b/src/zope/app/__init__.py
index bf99a9d..155a31d 100644
--- a/src/zope/app/__init__.py
+++ b/src/zope/app/__init__.py
@@ -1,8 +1,2 @@
 # this is a namespace package
-try:
-    import pkg_resources
-    pkg_resources.declare_namespace(__name__)
-except ImportError:
-    import pkgutil
-    __path__ = pkgutil.extend_path(__path__, __name__)
-
+__import__('pkg_resources').declare_namespace(__name__) # pragma: no cover
diff --git a/src/zope/app/dependable/__init__.py b/src/zope/app/dependable/__init__.py
index 7b69dba..b715241 100644
--- a/src/zope/app/dependable/__init__.py
+++ b/src/zope/app/dependable/__init__.py
@@ -13,11 +13,11 @@
 ##############################################################################
 """Dependable Framework.
 
-$Id$
 """
+
 __docformat__ = 'restructuredtext'
 
-from zope.interface import implements
+from zope.interface import implementer
 from zope.traversing.api import getParent, canonicalPath, getPath
 from zope.annotation.interfaces import IAnnotations
 
@@ -37,6 +37,7 @@ def __init__(self, context):
             parent = getParent(self.context)
         except TypeError:
             parent = None
+
         if parent is not None:
             try:
                 pp = getPath(parent)
@@ -53,7 +54,7 @@ def addPath(self, path):
         path = self._make_relative(path)
         annotations = IAnnotations(self.context)
         old = annotations.get(self.key, ())
-        fixed = map(self._make_relative, old)
+        fixed = [self._make_relative(o) for o in old]
         if path not in fixed:
             fixed.append(path)
         new = tuple(fixed)
@@ -65,7 +66,7 @@ def removePath(self, path):
         annotations = IAnnotations(self.context)
         old = annotations.get(self.key, ())
         if old:
-            fixed = map(self._make_relative, old)
+            fixed = [self._make_relative(o) for o in old]
             fixed = [loc for loc in fixed if loc != path]
             new = tuple(fixed)
             if new != old:
@@ -84,8 +85,15 @@ def _make_relative(self, path):
             path = canonicalPath(path)
             if path.startswith(self.pp):
                 path = path[self.pplen:]
-                while path.startswith("/"):
-                    path = path[1:]
+                # Now, the path should not actually begin with a /.
+                # canonicalPath doesn't allow trailing / in a path
+                # segment, and we already cut off the whole length of
+                # the parent, which we guaranteed to begin and end
+                # with a /. But it's possible that older dependencies
+                # than we test with could produce this scenario, so we
+                # leave it for BWC.
+                path = path.lstrip("/")
+
         return path
 
     def _make_absolute(self, path):
@@ -93,12 +101,10 @@ def _make_absolute(self, path):
             path = self.pp + path
         return path
 
-
+@implementer(IDependable)
 class Dependable(PathSetAnnotation):
     """See `IDependable`."""
 
-    implements(IDependable)
-
     key = "zope.app.dependable.Dependents"
 
     addDependent = PathSetAnnotation.addPath
diff --git a/src/zope/app/dependable/configure.zcml b/src/zope/app/dependable/configure.zcml
index e236c6c..fc19784 100644
--- a/src/zope/app/dependable/configure.zcml
+++ b/src/zope/app/dependable/configure.zcml
@@ -3,6 +3,8 @@
     xmlns:zcml="http://namespaces.zope.org/zcml"
     >
 
+  <include package="zope.component" file="meta.zcml" />
+
   <adapter
       factory="zope.app.dependable.Dependable"
       provides="zope.app.dependable.interfaces.IDependable"
diff --git a/src/zope/app/dependable/dependency.py b/src/zope/app/dependable/dependency.py
index 60ed384..747a878 100644
--- a/src/zope/app/dependable/dependency.py
+++ b/src/zope/app/dependable/dependency.py
@@ -16,6 +16,8 @@
 on an object having dependencies. It raises an exception if it's the
 case.
 """
+
+
 __docformat__ = 'restructuredtext'
 
 from zope.i18nmessageid import Message
@@ -44,4 +46,3 @@ def CheckDependency(event):
                 "dependents": ", ".join(dependents)
                 }
             raise DependencyError(Message(exception_msg, mapping=mapping))
-
diff --git a/src/zope/app/dependable/interfaces.py b/src/zope/app/dependable/interfaces.py
index 0baab0c..881be9a 100644
--- a/src/zope/app/dependable/interfaces.py
+++ b/src/zope/app/dependable/interfaces.py
@@ -12,9 +12,8 @@
 #
 ##############################################################################
 """Dependable framework interfaces
-
-$Id$
 """
+
 __docformat__ = 'restructuredtext'
 
 from zope.interface import Interface
diff --git a/src/zope/app/dependable/tests.py b/src/zope/app/dependable/tests.py
index 6c1d396..905e50e 100644
--- a/src/zope/app/dependable/tests.py
+++ b/src/zope/app/dependable/tests.py
@@ -12,16 +12,20 @@
 #
 ##############################################################################
 """Unit tests for Dependable class.
-
-$Id$
 """
-from unittest import TestCase, TestSuite, main, makeSuite
+
+import unittest
 
 from zope.annotation.attribute import AttributeAnnotations
 from zope.location.interfaces import ILocationInfo
-from zope.interface import implements, verify
+from zope.interface import implementer, verify, directlyProvides
 from zope.lifecycleevent import ObjectRemovedEvent
 
+from zope.location.interfaces import ILocationInfo
+
+from zope.testing.cleanup import CleanUp
+
+import zope.app.dependable
 from zope.app.dependable.dependency import CheckDependency
 from zope.app.dependable.interfaces import IDependable, DependencyError
 
@@ -30,10 +34,9 @@ class C(object):
     pass
 
 
+@implementer(IDependable, ILocationInfo)
 class DummyObject(object):
 
-    implements(IDependable, ILocationInfo)
-
     def dependents(self):
         return ['dependency1', 'dependency2']
 
@@ -41,11 +44,11 @@ def getPath(self):
         return '/dummy-object'
 
 
-class Test(TestCase):
+class TestDependable(unittest.TestCase):
 
-    def factory(self):
+    def factory(self, obj=None):
         from zope.app.dependable import Dependable
-        return Dependable(AttributeAnnotations(C()))
+        return Dependable(obj if obj is not None else AttributeAnnotations(C()))
 
     def testVerifyInterface(self):
         object = self.factory()
@@ -90,11 +93,51 @@ def testCheckDependency(self):
         event = ObjectRemovedEvent(obj, parent, 'oldName')
         self.assertRaises(DependencyError, CheckDependency, event)
 
+    def testWithParent(self):
+        grandparent = C()
+        grandparent.__name__ = 'root'
+
+        parent = C()
+        parent.__name__ = 'parent'
+        parent.__parent__ = grandparent
+
+        obj = AttributeAnnotations(C())
+        obj.__parent__ = parent
+        obj.__name__ = 'obj'
+
+        from zope.traversing.api import getPath
+
+        # If we can't get the parent path, it's just /
+        dependable = self.factory(obj)
+        self.assertEqual('/', dependable.pp)
+
+        # If we can, it's whatever it reported, always with a
+        # trailing /
+        directlyProvides(parent, ILocationInfo)
+        parent.getPath = lambda: '/root/parent'
+        dependable = self.factory(obj)
+        self.assertEqual('/root/parent/', dependable.pp)
+
+        parent.getPath = lambda: '/root/parent/'
+        dependable = self.factory(obj)
+        self.assertEqual('/root/parent/', dependable.pp)
+
+
+        dependable.addDependent('/root/parent/sibling/nephew')
+        dependents = list(dependable.dependents())
+        self.assertEqual(dependents, ['/root/parent/sibling/nephew'])
+
+
+class TestConfiguration(CleanUp, unittest.TestCase):
+
+    def test_configuration(self):
+        from zope.configuration import xmlconfig
+        xmlconfig.file('configure.zcml', package=zope.app.dependable)
+
 
 def test_suite():
-    return TestSuite((
-        makeSuite(Test),
-        ))
+    return unittest.defaultTestLoader.loadTestsFromName(__name__)
+
 
-if __name__=='__main__':
-    main(defaultTest='test_suite')
+if __name__=='__main__': # pragma: no cover
+    unittest.main(defaultTest='test_suite')
diff --git a/tox.ini b/tox.ini
index 6fef181..c758890 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,31 +1,9 @@
 [tox]
 envlist =
-    py26,py27
+    py27, pypy, py35, py36
 
 [testenv]
 commands =
-    python setup.py test -q
-# without explicit deps, setup.py test will download a bunch of eggs into $PWD
+    zope-testrunner --test-path=src
 deps =
-    zope.annotation
-    zope.exceptions
-    zope.i18nmessageid
-    zope.interface
-    zope.lifecycleevent
-    zope.location
-    zope.traversing
-
-[testenv:coverage]
-basepython =
-    python2.7
-commands =
-#   The installed version messes up nose's test discovery / coverage reporting
-#   So, we uninstall that from the environment, and then install the editable
-#   version, before running nosetests.
-    pip uninstall -y zope.app.dependable
-    pip install -e .
-    nosetests --with-xunit --with-xcoverage
-deps =
-    nose
-    coverage
-    nosexcover
+    .[test]