ABBREX – Free Acronym/Abbreviation Expander
http://abbrex.com/

ABBREX is a free acronym / abbreviation expander add-on for Firefox and Chrome. Once you install it on your browser, it displays the meanings of abbreviations and acronyms in tooltips when you hover over them. It works automatically and unobtrusively on any site you visit. No more constantly having to look up abbreviations when you are surfing the web! It is community-driven so ABBREX abbreviation database keeps growing every day and you can contribute by adding abbreviations too! This has been added to the tools section of Research Resources Subject Tracer™ Information Blog.