pip is a replacement for easy_install. It uses mostly the same techniques for finding packages, so packages that were made easy_installable should be pip-installable as well.
pip is meant to improve on easy_install. Some of the improvements:
* All packages are downloaded before installation. Partially-completed installation doesn’t occur as a result.
* Care is taken to present useful output on the console.
* The reasons for actions are kept track of. For instance, if a package is being installed, pip keeps track of why that package was required.
* Error messages should be useful.
* The code is relatively concise and cohesive, making it easier to use programmatically.
* Packages don’t have to be installed as egg archives, they can be installed flat (while keeping the egg metadata).
* Native support for other version control systems (Git, Mercurial and Bazaar)
* Maybe uninstallation will get added. (It might get added to easy_install, but I think the chance for pip is higher.)
Also, pip will eventually be merged directly with poacheggs, making it simple to define fixed sets of requirements and reliably reproduce a set of packages.
pip is complementary with virtualenv, and it is encouraged that you use virtualenv to isolate your installation.
