Unfortunately most linux systems do not support multi-version installs or installs local to a user or path.

This comes very close: http://nixos.org/nixos/

An OS solution which allowed for versioned packages to be installed on a per-project base. That’d be something…

aptly put. you might be onto something.

Groan. Well put, but still, groan. 8-)

Whats apt going to do for me on Redhat/CentOS?

The problem with package managers is the same as npm/gem.

not much, but it was harder to work yum into a relevant sentence.

..yum.