Community Expansion Pack, a compilation of various useful things created by NWN community. A must have one!
As read at nwvault.ign.com:
"For those of you who are new to the CEP, this is a collection of hak packs from the previous six years of custom content, designed to work with BioWare's Neverwinter Nights. You’ll find some of the best and most popular work available for NWN. Now, the CEP Team hasn't just sat back and mashed these haks into one huge collection of material. As you look through the content you’ll notice model, animation and texture corrections, new scripts, and completely new content unique to the CEP itself. All of this has been designed to work alongside the official content of Neverwinter Nights and all patch updates by BioWare; so you will be able to enjoy their high quality with as little fuss as possible.
The CEP Team has been hard at work, trying to answer that call, and together they have assembled several hundred individual haks into what is one of their greatest works so far."