purely package-based/oriented solution

[Andriy Gapon]

Sorry if this is something obvious or a FAQ.

Is there a tool for purely package-based management of third-party software?
That is, something that meets the following criteria:
1. doesn't require ports tree
2. works similarly to package installation in FreeBSD installer
3. can properly handle upgrading packages (including dependencies)
4. can check remote package repositories and, based on timestamp or
INDEX, can find new versions for installed packages
5. can verify that all dependencies would be met before downloading all
packages in full (e.g. based on INDEX data or can download initial
blocks of packages, so that package metadata could be extracted and
examined).

-- 
Andriy Gapon