| Halloween | | - | |
| Hand Drawn Icons | | - | |
| HiVisGnome | | - | |
| HiVisGnome Big | | - | |
| HiVisGnome Jumbo | | - | |
| HypeSonic | | - | |
| IE6 Toolbar | | - | |
| ISNO | | - | |
| In The Dark | | - | |
| Infernox | | - | |
| Internet Explorer 5 Mac Theme | | - | |
| Iowa State Cyclones Theme | | - | |
| Iron | | - | |
| Jupiter Firefox | | - | |
| Just Black | | - | |
| Kempelton Reloaded | | - | |
| Kempelton Reloaded Large | | - | |
| LCARStrek | | - | |
| LavaFox V1 | | - | |
| LavaFox V1-Blue | | - | |
| LavaFox V1-Green | | - | |
| LavaFox V1-Purple | | - | |
| Littlefox | | - | |
| Luna Blue | | - | |
| M is for Minimalism | | - | |
| MX3 | | - | |
| MZ8 | | - | |
| Mac OSX Theme | | - | |
| MacOSX Theme (Firefox 4 Linux) | | - | |
| MacOSX Theme (Firefox 4) | | - | |
| Machrome | | - | |
| Maczilla Brazil | | - | |
| Maczilla Classic | | - | |
| Maczilla Default | | - | |
| Maczilla Graphite | | - | |
| Maxi | | - | |
| Metal | | - | |
| Metal Lion | | - | |
| Metal Lion Australis Graphite | | - | |
| Metal Lion Australis Theme | | - | |
| Metal Lion Australis Tiger | | - | |
| Metal Lion Australis Tiger SP | | - | |
| Metal Lion － Brushed iCe | | - | |
| Metal Lion － iCe | | - | |
| Metal for Firefox | | - | |
| MicroFox | | - | |
| Microfirefox | | - | |
| MidnightFox | | - | |
| Modern Aluminum | | - | |
| Modern Modoki | | - | |
