If nothing else, we humans are good at pushing the limits of common sense just to see what will happen. Installing a ridiculous number of add-ons (and taking pictures, of course) has long been a tradition for Internet Explorer, uh, “enthusiasts,” and now the Firefox fans are carrying the torch: Inspired by a 100-extension test back in February, the folks at CyberNotes doubled their pleasure and installed 200 add-ons in Firefox 2. The result? Well, it isn’t pretty. Predictably, the screen is almost totally overwhelmed by toolbars, leaving but a few square inches for actually navigating the web. Perhaps more impressive is the Tools menu which takes up almost two full screen heights. What’s impressive, though, is even after two hundred add-ons are installed, CyberNotes finds that Firefox still, essentially, works, and takes up a hefty but not outlandish 200MB of RAM
http://tech.cybernetnews.com/2006/12/06/cybernotes-200-firefox-extensions-installed-at-one-time/