Spring RTS Engine

So, after ditching Ye Olde Nehe Rendering Methods and learning a bit of GLSL, I was told, I don't recall who by, that you don't actually write shaders. Apparently you write programs that write shaders. Does anyone have any resources on this?

all graphic cards are not equal. thus there is a compiler who takes your standardized statements in glsl and compiles them into something cg- assembly like depending on your graphics card.

One of the reasons everyone told me to shoove learning cg - because (Optimizing for it, means to fine adjust it for just one vendor and there for just one product) thus glsl and in near opt compilers we thrust