This texture pack is intended for birds or those who are filled with nuclear rage at the mere thought of glass.
Details:
-All Glass is completely invisible.
-Block textures are separate from item textures, allowing you to see the glass in your inventory and craft normally. The translucency only comes into effect on placed blocks.
Check out my Reduced Opacity Colored Glass pack, if you want a similar effect and still be able to (theoretically) build with glass.