This skin is by a long shot, the best of the best. All others fall far, far short. I have tried and tested numerous skins that just don't have the heart and soul this one does. It was clearly a labor of love for the developer. It has a beautifully crafted layout with clean, crisp icons, a handful of add-ons that work alongside it, such as the fox options, noia extra buttons, etc.
That being said, it is out dated. The only options for skinning these days are pathetic background images. Either the developers have gotten lazy, or the competent ones have given up on Firefox. A picture of stars overlaid on a clone of Google Chrome is not the Firefox that I have grown to love over the last decade. Noia Fox is.
And on a side note, this Theme works on the newest version of Firefox, which as I type is 45. Unfortunately, it is only set to be compatible up to version 40. I can tell you, it works on version 45 exactly as well as it did on version 40. If you want to experience a full-fledged, artfully crafted, masterfully designed Firefox theme like this, follow the instructions on this link: