Ripple is more aimed at dependency management of components. Much like NuGet (in fact it uses NuGet) combined with direct fetching from Git repos, better resolving of dependencies and such.
OneGet is more aimed at installing system components. It is like Chocolatey (and in fact uses Chocolatey under the hood).
Thanks, looks like I totally misunderstood oneget. It is more intended to pave a clean machine with the correct products and libraries?
Ripple can be considered as another solution-level package manager, much like NuGet. That's as far as I can tell there's any relationship :)