Is it possible to install Gentoo portage manager (emerge) on Ubuntu?

Question

And vice versa?
For example install apt-get on Gentoo and connect Ubuntu's repositories.
And if it is possible how can I do it? (at least in general terms)

Answer 1

You might be interested in Gentoo Prefix.

Usually, Gentoo's Portage installs in the root of the filesystem hierarchy, '/'. On systems other than Gentoo Linux, this usually results in problems, due to conflicts of software packages, unless the OS is adapted like Gentoo/FreeBSD. Instead, Gentoo Prefix installs with an offset, allowing to install in another location in the filesystem hierarchy, hence avoiding conflicts. Next to this offset, Gentoo Prefix runs unprivileged, meaning no root user or rights are required to use it.

Answer 2

Technically you might be able to do. But is is going to be highly experimental and not very useful and very unlikely to teach you anything.