EasyInstall is a package manager for the Python programming language that provides a standard format for distributing Python programs and libraries (based on the Python Eggs wrapper). easy_install is a module bundled with setuptools, a third-party library meant to enhance the Python standard library's distutils (Distribution utilities). It is analogous to RubyGems for the Ruby programming language.
By default, EasyInstall looks in the Python Package Index (PyPI) for the desired packages and uses the metadata there to download and install the package and its dependencies. It is also hosted itself on the PyPI.