Added trove classifiers for supported Python versions.
diff --git a/setup.py b/setup.py
index 9ebda26..2c794c8 100644
--- a/setup.py
+++ b/setup.py
@@ -26,6 +26,10 @@
     "License :: OSI Approved :: MIT License",
     "Operating System :: OS Independent",
     "Programming Language :: Python",
+    "Programming Language :: Python :: 2.3",
+    "Programming Language :: Python :: 2.4",
+    "Programming Language :: Python :: 2.5",
+    "Programming Language :: Python :: 2.6",
     "Topic :: Software Development :: Libraries :: Python Modules",
     "Topic :: Text Processing :: Markup",
 ]