Quote Originally Posted by Cabhan View Post
Gentoo USE flags basically correspond to preprocessor symbols for the code, that allows the code to compile differently. They work in Gentoo because Gentoo is source-based: for a binary package, you obviously cannot change the way the package was compiled.
Well, USE flags really can be used for almost anything. Yes, they can be used to pass compile time options and, hence, to tweak the dependencies. But they can be used for many other things. There are quite a few binary packages in portage, for example, and their ebuilds usually check the the amd64 or x86 use flags to decide which binary version to download. They can also be used to delete components that are not going to work without a certain dependency. I do this in the fvwm ebuild with scripted components that are not going to work because of missing dependencies when a given use flag is not selected. They are not compiled components.

However, as per the original question goes:

Quote Originally Posted by Compintuit View Post
So I'm asking if anyone knows of, or if it could even be built, a package manager that would install and manage tarballs I download, as well as packages from repositories.
I think that you should just use Gentoo. Gentoo can manage anything. If it's a source package, there's a big chance that a basic ebuild will compile it. You can always look in many places to find an ebuild, probably it exists already. If you need something that's rpm-only, make it DEPEND on rpm2targz, then use the ebuild to put each file on the correct place. It can deal with source or binary packages of any kind, and the only limits of ebuilds are those of bash, since that's what they ultimately are: bash scripts.

As a side note, is there any other package system that uses something like use flags? I think they're awesomely efficient.
Well, USE flags are a Gentoo thing as well.