It's not a texture pack. It's actually a modification of the installer to support GLSL Shaders. So, in short, it's a new graphics system for the same game.

On a related note, this crazy son of a bitch is trying to explode the universe by making a computer in minecraft, which is run by java, which is run by computers. So, essentially, he's making a computer in a computer in a computer in a computer. :l
If you want to see the ALU he made, it's all up in here. It's fucking crazy huge.