Fedora uses yum so to install KWrite you would open a console and type yum install kwrite If you are unsure of the name of a package, you can use yum list with wildcards to see all the packages with a word as part of the package name — for example yum list *network* will list all available packages with "network" as part of the name. Casting even wider, yum search mpeg will list all packages that either have mpeg in the name or in the description of the package.
