Looking for a lean, mean Mac only Firefox theme? If you want Firefox to look a little more minimal on your Apple-powered PC, then look no further than Leanfox. This theme has all the style and substance you need, and little to no distractions in the interface.
Here is a little more about the theme, from the developer:
The aim of this theme is to be no-nonsense, clean, utility like, compact, minimal. This theme has no extra lines or details anywhere: the tabs blend into the main chrome and only the active tab is really highlighted – making you concentrate on only one thing at a time. There’s also minimal separation between the tabs as it became apparent that separating lines were just distracting.
Only downside to this theme is it is Mac only for now (no Windows version yet) but maybe if we leave the author enough nice comments showing him the need for Windows version, he might reconsider.