Yolk has moved to github! https://github.com/cakebread/yolk
Yolk is a Python library and command-line tool for obtaining information about packages installed by setuptools and packages on PyPI (Python Package Index a.k.a. The Cheese Shop)
Features
List eggs or packages installed by setuptools
Determine which packages are activated or not (—multi-version)
Examine package metadata
Show dependencies of packages if available
Query PyPI for various package information using XML-RPC interface