Firefox Personas, the lightweight themes for the Firefox browser, are still pretty new to the Mozilla user base our there. 
With that in mind, I thought it might be handy to guide you through the process when it comes to adding a new Persona theme to your browser, removing a Persona theme from your browser, and how to chance through Persona themes – once you have several saved to your system.

Sage was once one of the more popular RSS feed reading add-ons for Firefox.  However, time went by, years went on and these days it is not making much news.  However, if you still need a lightweight feed reader, there is now Sage-Too.  This is a continuation of the original project to keep it up to date with today’s Firefox browser versions. 
Some of the features include:

Reads RSS (2.0, 1.0, 0.9x) and Atom feeds
Feed Discovery
Integrates with Firefox’s bookmark [...]

Maybe your not a RSS feed junkie like I am, but you do like to do some occasional headline tracking from time to time.  Simple RSS Reader might be the extension for you, as it does exactly what you would think.  It is a simple little RSS reader (minus the geeky complications).
The hardest part about Simple RSS Reader is adding the RSS feeds.  Just click on the blue RSS icon and give a name and URL to each.  That [...]

Simple, yet different the hmmXP theme makes a perfect companion for Firefox.

No huge distractions here. It is simple, lightweight but still gives you that visual refresh you might be looking for when changing your Firefox theme around. The light blueish-purple is a welcome too as it is all very pleasing to the eye. Mix that with the hint of green and the theme – it is delicious. I would lick it if I could, but I [...]

After reviewing some of the most recent comments on some of the past posts here on Firefox Facts, I saw that somebody had suggested the Brief RSS reader extension. I had never heard of it till reading that post.
Always interested in seeing new readers I gave it a shot and I do have to say it is pretty impressive.
I might even say it is better than Sage.

It is focused on giving you a lightweight RSS [...]