Counter-Strike 1.6 Dark Inferno is a modification of the original Counter-Strike 1.6 , but the "Engine" of this client game kit wasn't modified ! You can play the original game but with new experience such as , new gameplay music , new background , new colors for the menu , new in game aspect . 
It run and on the worst pc . This client game kit works fine with higher FPS and no lag . Counter-Strike 1.6 is one of the most played FPS game in the history , it appeard in 2001 , after Half-Life release ( 1999 ) . This game is played and nowadays and with this client game kit , you can stay updated at all . 

The newest features are : 
 [$] Protection against slowhack methods [ This problem was generaly at all client game kits and now it's done ] 
 [$] New game menu image , sound and colors 
 [$] New textures of the maps and with a higly FPS 
 [$] A list of servers updated weekly 
 [$] This game pack comes with the latest bots 
 [$] This game is compatible with all internet servers 
 [$] The name and configurations are saved after exiting the game 
 [$] Just 372Mb archive size 

SnapShots : https://imgur.com/a/cymd7