I have had this idea kicking around for a while now, and have finally done a bit of work on it. I use font book quite a bit, I like its simplicity, but a few features could really improve it. The main thing that would make finding fonts quicker and easier is a tagging system, shown in this little mockup. Whenever you add a new font - 3, you can assign tags to it that you have defined. These tags - 1, can then be used to search for a font based on its characteristics. You can change tags assigned to existing fonts - 4, and when browsing through a collection the weight variations appear in a separate popup - 2, to save time instead of drilling down for each font. How complicated would it be to make some sort of patch with this functionality? or are there any existing offline mac programs that can do this? I havent found anything quite like it. Any feedback/input would be great!