Made use of versioneer, with a few modifications.

.gitattributes

@@ -1 +1,2 @@
 * text=auto
+lib/matplotlib/_version.py export-subst

MANIFEST.in

@@ -17,3 +17,5 @@ recursive-include doc *
 recursive-include src  *.cpp *.c *.h *.m
 recursive-include lib *
 recursive-include extern *
+include versioneer.py
+include lib/matplotlib/_version.py

lib/matplotlib/__init__.py

@@ -129,7 +129,12 @@
 from matplotlib.externals.six.moves.urllib.request import urlopen
 from matplotlib.externals.six.moves import reload_module as reload
 
-__version__ = str('1.5.dev1')
+# Get the version from the _version.py versioneer file. For a git checkout,
+# this is computed based on the number of commits since the last tag.
+from ._version import get_versions
+__version__ = str(get_versions()['version'])
+del get_versions
+
 __version__numpy__ = str('1.6')  # minimum required numpy version
 
 try: