Q:

Why does installing Kubuntu-desktop prompt me to remove "lpr"?

I want to install the full kubuntu desktop from the software centre, when I hit install it pops out a window that says "To install kubuntu-desktop, these items must be removed:" with this package listed below.
I don't really know much about this package but I want to know the reason why kubuntu-desktop wants to remove it. Also I wanna make sure that removing this package won't affect unity's features or whatever.

A:

lpr is the BSD print spooler and utilities. It typically isn't used in the various *buntu flavors (Ubuntu, Ubuntu Gnome, Ubuntu Studio, Kubuntu, Xubuntu, and Lubuntu) anymore. A newer variant, included in the cups-bsd package, provides the same functionality and includes support for Internet Printing Protocol.
The package kubuntu-desktop recommends the package cups-bsd. It replaces the lpr package -- that's why the package manager wants to remove it.
As to why you have lpr installed now, hard to say. Given that cups-bsd is standard across the *buntu flavors, I'd say you're safe to proceed.

