diff --git a/.gitignore b/.gitignore
index 69478c95..021dc356 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,8 @@
 docs/_build
 build
+dist
 env
+hashindex.c
 *.egg-info
 *.pyc
 *.pyo
diff --git a/darc/__init__.py b/darc/__init__.py
index c2191673..c37c5d93 100644
--- a/darc/__init__.py
+++ b/darc/__init__.py
@@ -1 +1,4 @@
 # This is a python package
+
+__version__ = '0.5'
+__release__ = __version__ + 'dev'
diff --git a/docs/conf.py b/docs/conf.py
index 1cb31fa4..425d064a 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -11,7 +11,7 @@
 # All configuration values have a default; values that are commented out
 # serve to show the default.
 
-import sys, os
+import sys, os, darc
 
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
@@ -48,9 +48,9 @@ copyright = u'2010-2011, Jonas Borgström'
 # built documents.
 #
 # The short X.Y version.
-version = '0.1'
+version = darc.__release__
 # The full version, including alpha/beta/rc tags.
-release = '0.1'
+release = darc.__release__
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
diff --git a/setup.cfg b/setup.cfg
new file mode 100644
index 00000000..3c2fdf51
--- /dev/null
+++ b/setup.cfg
@@ -0,0 +1,2 @@
+[egg_info]
+tag_build = dev
diff --git a/setup.py b/setup.py
index 25f4ef3f..285cbceb 100644
--- a/setup.py
+++ b/setup.py
@@ -3,6 +3,16 @@
 import os
 import sys
 from glob import glob
+import darc
+
+min_python = (2, 5)
+if sys.version_info < min_python:
+    print "Darc requires Python %d.%d or later" % min_python
+    sys.exit(1)
+
+if sys.version_info >= (3,):
+    print "Darc doesn't support Python 3 (yet)"
+    sys.exit(1)
 
 try:
     import Cython
@@ -17,6 +27,7 @@ hashindex_sources = ['darc/hashindex.pyx', 'darc/_hashindex.c']
 try:
     from Cython.Distutils import build_ext
     import Cython.Compiler.Main as cython_compiler
+
     class Sdist(sdist):
         def __init__(self, *args, **kwargs):
             for src in glob('darc/*.pyx'):
@@ -43,17 +54,17 @@ if sys.version_info < (2, 7):
 
 
 setup(name='darc',
-      version='0.1',
+      version=darc.__version__,
       author='Jonas Borgström',
       author_email='jonas@borgstrom.se',
       url='http://github.com/jborg/darc/',
       packages=['darc'],
-      cmdclass = {'build_ext': build_ext, 'sdist': Sdist},
+      cmdclass={'build_ext': build_ext, 'sdist': Sdist},
       ext_modules=[
       Extension('darc._speedups', ['darc/_speedups.c']),
       Extension('darc.hashindex', hashindex_sources)],
       install_requires=dependencies,
-      entry_points = {
+      entry_points={
         'console_scripts': [
             'darc = darc.archiver:main',
         ]