On Mon, 15 May 2000, Mocha wrote:

>    2. change the package system so it can deal with having different
>       versions of the same package.

It can, if they have different names, and if installed files are
renamed or moved so that no files of one are overwritten by the other.

How else? For the typical package, each version installs identically
named files, so what would it mean to have two versions of any
arbitrary package installed?