High Quality Content by WIKIPEDIA articles! Sage is a lightweight RSS and atom feed aggregator extension for the Mozilla Firefox web browser. The extension was developed by Peter Andrews and Erik Arvidsson. The current stable release of Sage is version 1.4.5, compatible with Firefox 3.6, released on February 8, 2010. Sage won the most "Most Innovative" award in Mozilla's 2006 "Extend Firefox" competition.Mozilla Firefox is a free and open source web browser descended from the Mozilla Application Suite and managed by Mozilla Corporation. A Net Applications statistic put Firefox at 24.59% of the recorded usage share of web browsers as of April 2010, making it the second most popular browser in terms of current use worldwide after Microsoft's Internet Explorer. Other sources put Firefox's usage share between 20% and 32%.