Met Mozilla Firefox Personas kunt u het uiterlijk van Firefox aanpassen. Dit gebeurt aan de hand van skins die via personas toegepast worden zonder eerst bestanden te hoeven downloaden. De veranderingen die 0.9.1 met zich meebrengt staan hieronder:
In this version, the Persona selector is dynamically loaded and populated from a JSON feed and all designs are loaded via URLs to remote resources. All changes to the browser chrome are applied instantly, with no need to restart.

We’ll shortly be releasing an API that will allow developers and designers to submit Personas that are based on Web content, including support for anything that can load in a content window such as HTML, CSS, PNG, JPG, Javascript, SVG and Canvas.