An absolute must! Two Thumbs Way UP!!!! Rated 5 out of 5 stars
Have used it for 2 weeks now and it is by far the most important and critical add-on for Firefox. An absolute must!
My favorite feature is that you can approve selected (friendly) scripts while blocking annoying and/or malicious scripts. For example; I use wunderground.com as my weather source but it has very annoying banner ads that enlarge if you mouse over them. By allowing only 2 of the 7 scripts on their site, I get the updated weather without any banners what so ever. Here is another; I can watch The Daily Show (.com) now without commercials!!
I've read some (IMO unfairly/misdirected) negative reviews about this add-on and I can't help but wonder if these reviewers really understand scripts, what this add-on actually does and how it relates to the problem that they are having. All I can say is that this extension works brilliantly for me and exceeds all my expectations.
While it requires your approval/decision on which scripts to allow every time you visit a "new" site, it does remember or "learn" your settings so that you don't have to re-input for your routine sites. Some may find this a hassle, but if you have ever been infected with a rootkit virus, lost all your files and spent untold hours/days/weeks debugging/reinstalling/rebuilding your PC's OS, software, Documents, files, etc., then a couple seconds of prevention before entering an unknown website is a small price to pay my friend.
However, if you are less concerned with preventive security and would prefer to not be bothered with script management tasks while surfing, I recommend that you look at the reactionary "YesScript" add-on instead.
If you don't understand what scripts are consider spending an hour googling up some info on the subject. If you do, I guarantee you that you will install this add-on immediately and use it from now on (plus a basic understanding of scripts will lend to a better understanding of how to operate this add-on).
After using this add-on I cannot conceive surfing without it. Nor can I comprehend how anyone (who understands it) could give it anything under 5 stars and a glowing review.
Two Thumbs Way UP!!!!
and a big thanks to the designer(s)!