This is the proprietary binary video driver from NVidia for the X.Org 
X-server.  This package does not include the kernel-module - it is a
part of the nvidia-kernel package at SlackBuilds.org.

Since this nvidia-driver conflicts with some files of xorg, it's a bit 
complex to install/uninstall the driver.  However, installation of the
nvidia-driver package itself backs up the conflicting files and puts the
nvidia-specific files into place.

Heinz Wiesinger, the author of the build script, has written a script called
nvidia-switch, which can be used to switch between the stock xorg driver and
the nvidia driver, but it will not edit xorg.conf for you; you have to do 
that manually.  The nvidia-switch script is installed to /usr/sbin.

Usage of nvidia-switch:
  nvidia-switch --xorg	 <-->  switch to the stock xorg files
  nvidia-switch --nvidia  <--> switch to the proprietary nvidia files

Before uninstalling this package, it is important that you execute 
'nvidia-switch --xorg', which will switch back to the stock xorg files. 
If you forget to do this, you'll have to do the switch manually, or xorg 
won't work on next startup.  Here are the affected files:
  /usr/lib/libGL.so.1.2
  /usr/include/GL/{gl.h glx.h glxext.h glext.h}
  /usr/lib/xorg/modules/extensions/{libGLcore.so libGLcore.la libglx.so libglx.la}

This also requires the nvidia-kernel package from SlackBuilds.org.