Features

For the End User

• An optional new configuration system, making it much easier to operate upon groups of related packages, much easier to maintain multiple systems (or chroots) and much easier to set options on a per-package or per-repository basis.
• Performance. Paludis can be an order of magnitude faster than other package managers.
• Low dependency bloat. No Python, no big external crypto libraries.
• Native security (GLSA) integration.
• Proper multiple repository support, not constrained by a limited 'overlay' model.
• Support for repositories containing things other than ebuilds.
• License filtering.
• Hook scripts, for running code after a certain action occurs.
• User definable package sets.
• Ability to sync multiple repositories, natively, using SVN, CVS, Git etc.
• Ability to uninstall packages with dependencies, and safely remove unneeded packages.
• Ability to continue with a collection of installs after a failure, and to resume failed compiles far more flexibly than offered by Portage.
• Ability to see why a package is really being pulled in, rather than relying upon the rather crude '--tree' offered by Portage.
• Much improved output: cave show makes it easy to get a useful summary of information about a package, and cave resolve can be configured to show relevant information (e.g. USE flag descriptions and an explanation of why a package is being pulled in).
• Secure (un)installation of set*id files, preventing your system from being left vulnerable after having replaced a vulnerable application.
• Ability to use slot, use, repository and ranged version dependencies in dependency specifications.
• Ability to see all packages that need unmasking in one go, rather than one package at a time.
• Ability to automatically reinstall scm (svn, cvs etc.) packages after a given period (daily, weekly, ...).
• Ability to manage packages even where no ebuild is available.

For the Ebuild Developer

• Full and correct circular dependency resolution.
• Deep dependency resolution even when not upgrading everything.
• Support for 'experimental' (read: 'still not implemented in Portage') EAPI proposals (use dependencies, ranged version specs, -scm and -try version specs, src_uri arrows etc).
• Ability to deliver news items to the end user.
• Much more useful diagnostics.

For the Programmer

• Proper client / library separation.
• API documentation and code examples.
• A sane OO API.
• Consistent interfaces for different repository types.
• Test suites and extensive static checking, to check the impact of changes.
• Type safe interfaces, for catching programming errors at compile time.
• A choice of programming language for external tools.