One of the biggest frustrations for most Minecraft players is the fact that glass is not always the easiest to work with – or look through. In an ideal Minecraft world you could create large windows that would provide panoramic views of the outside terrain. Unfortunately, all you’re likely to get with the current glass system is a tiled effect that besmirches the beauty of the world. The Better Glass mod fixes this problem, making multiple glass blocks merge into single seamless sheets.
Surviving Minecraft, Minecraft Adventures! 
That is a great improvement, it’s silly to think it isn’t in the default pack…
Do you know of any mod, that makes glass translucent?
That allows tint the glass, so that the pixels aren’t always 100% opaque or 100% transparent.