I found a different way to get shadows in Minecraft ! This one,it's not a mod. It's a pic called "lightmap0.png" in texture packs! Just move the file into the "enviroment" folder in the texture pack and put your Brightness to 50% or Moody! This might be a really nice alternative for people who cannot run SEUS (Sonic Ether's Unbeliveable Shader).

Download - http://ge.tt/8lN66cL/v/0?c

Tutorial

1.Download the picture


2.Rename the picture to lightmap0.png

3.Replace the picture in enviroment


Don't know where is enviroment folder ? Inside minecraft.jar =.=

4.Enjoy !

side note : it's need optifine !