daawsomest

Hello, I have some pretty basic questions to ask, I mainly write Bukkit plugins and not mods, so please forgive me. I would like to know if forge can be used to write client side only mods. If so, what can it do and what can't it? I assume it is possible because people have created hacked clients, but I am not sure if that was done with forge or not. I know it could add new stuff to the game but could it move the player or display text on the screen? Thanks, Daawsomest