This is the kernel-module needed by the proprietary binary nvidia driver.
You also need the nvidia-driver package from SlackBuilds.org.
To build the package for a kernel different from the running one,
start the script setting the KERNEL variable as in
KERNEL=3.18.19 ./nvidia-kernel.SlackBuild
A default config file is placed at /usr/share/X11/xorg.conf.d/10-nvidia.conf
to make sure that X loads the nvidia module. If you need to make changes,
copy that file to /etc/X11/xorg.conf.d/ and edit the copy. You do not need
this file at all if you have a proper and complete xorg.conf.
The xf86-video-nouveau-blacklist package from /extra is required.
29c9501ad7