I don't think it is an either or. But being in the standard really aids in discovery and provides an interface to allow it to work just as well for everyone.

I don't think it is an either or. But being in the standard really aids in discovery and provides an interface to allow it to work just as well for everyone. Ad for package maanagers, first you have to get everyone to agree on an approach. So the first question is binary, source, or either. Then figure out if it is distributed(e.g. specify the host in the dependency) or centralized. For me I would something that is mixed binary/source and distributed. I do not want to be required pull binaries from a central host or require a central DB of locations. It would be good to have, just not mandatory. Then, like you said, the build system. I am not sure that this needs to be any one system. If you look at CMake external projects it is close to being really good with allowing most source control systems/url's. What it lacks is the ability to use versioning(such as git commit/release and per user/per system caching) It also does a git check on each build. But specifying dependencies like Carthage, used for Xcode, would a nice starting point