RT Linux is a specific distribution of Linux, as is Fedora. You can install RT Linux over Fedora, but RT Linux isn't a program you install in a Fedora installation, but an entirely different installation altogether (and meant for different things; RT Linux is meant for specialty devices where the machine needs to manage devices and calculations in Real-time whereas Fedora is more a desktop/server distribution.)

Fedora Core and later Fedora !

Fedora is a desktop-oriented Linux distribution, and ususally features Red Hat's more experimental software.

Most desktop Linux distributions (Ubuntu, Fedora, PCLinuxOS, OpenSUSE) are equally suitable for laptops.

The best resource one could find for this type of information is the Fedora Project's website. It has helpful information for those looking to work with the company.