NLC is a hardcore total conversion for Stalker Shadow of Chernobyl that completely overhauls the story, gameplay and overall feel of the game, in all of these fields, adding content to it. It was created in the earlieast day's of Stalker modding by Syak, as a way to add new path's beetween territories, however as he worked on the mod the more mechanics he introduced and the more he changed, the more people he recruited and, getting incrementally bigger and bigger until we get to NLC7, the last NLC version that was made with Syak at the helm. The latest NLC7 version is Build 3.0.
The mod being so old, many teams and different modders have taken the challenge to build upon and change the original vision of the mod as they please, you have various different aims with each of them, some seek to simplify the game and make it less hardcore and more approachable, other's seek to make it harder and more lenghty, while other's try to improve the game's systems to better aid the player, keeping the game hard while offering important Quality of Life features.