Wizz RSS for Firefox is no longer maintained or supported. However, a new Wizz RSS project has recently been started:
https://github.com/wizzrssfeeds/WizzRSSFeeds
It will be a complete ground up rewrite and uses new technologies such as ES6, React & Redux, DDP and Electron instead of XUL and XPCOM. Feel free to join!
Many thanks to all contributors that helped me maintain this project over the years: Alain Romedenne (translations), Andreas Raddes (new icon), David Desrosiers (icons), Frederic Fays (translations), Harshit Dwivedi (MEPIS support) and many more who contributed code or ideas or alerted issues on my bugtracker. Special thanks to Mounir Lamouri for maintaining the project in the past years!
Wizz RSS for Firefox is a lightweight and easy to use extension that allows you to subscribe to feeds with just a few clicks. It supports Live Bookmarks, Search Engines, browser popup, keyboard shortcuts and all other useful features.
The most recent stable release can be found here: http://people.skolelinux.org/pere/blog/Downloads_firefox-addons-stable.html#w2r
Here are a few screenshots of Wizz RSS for Firefox:
To get started with Wizz RSS for Firefox have a look at this page: https://support.mozilla.org/en-US/kb/wizzrssfeeds-rss-feeds-add-remove
Please note that new versions of Wizz RSS for Firefox are no longer be released; the latest stable release was v2.1.4 (2014 02 13). The addons website archive version is however still accessible here:
https://addons.mozilla.org/en-US/firefox/addon/wizzrssfeeds/versions/?page=1&sort=featured
Wizz RSS for Firefox is distributed under MPL 1.1 and GPL 2 or later, except in countries where such licensing does not provide the user with this freedom (see http://www.gnu.org/licenses/gpl-q.html#Licensing).
Downloads of Wizz RSS for Ubuntu are available here – https://launchpad.net/wizzrss
If you find the whole launchpad thing as confusing as I do, you can the latest .deb installation file here: – http://wizzrss.com/wizzrss_12.07.11_all.deb