Feed The Beast

I love the mod packs that FTB has, especially Ultimate and Resurrection. But I'm wondering why a launcher hasn't been developed that has an archive of mods that the user can select from to create a custom mod pack. It tells you which mods are compatible with one another, and when game instability is reached (Expl. when too many mods could possibly causing game lag and/or crash) to help you better select your mods. And once you've chosen all your mods, and maybe allowing you to name the mod pack, the launcher then allows you to directly download those mods from the archive and let's you start playing.