You can see Framework Scanner in action here.
Fleegix.js comes out looking pretty good in this online demo, with only 6 additional global symbols detected -- and as it turns out, 2 of those are false positives. One of those is an undeclared local variable which was leaking out into the global namespace (and has subsequently been fixed). The other is an old-style "onunload" which I can't find any references to in the code anywhere -- perhaps it existed in some plugin somewhere at some point in the past, I'm not sure.
The online demo includes an "Analyze your own scripts" feature, so I re-ran the test with the most up-to-date version of the library on GitHub, and it correctly found only 4 global symbols: (
This stacks up pretty well with Dojo 1.2.3 (5), JQuery 1.3 (2 -- presumably
$, which they use as an alias for it), Prototype 18.104.22.168 (25, wow), YUI 2.6.0 (5), and MochiKit 1.3.1 (243 (robot Jesus!), or 11 with
__export__ set to false).
Really nice to see Fleegix.js showing up with such illustrious company -- and with the magic of alphabetical order, it's right there at the top, sweet!
Framework Scanner is pretty cool -- since more people are mixing-and-matching toolkits, knowing what kind of impact they have on the global namespace is really helpful. It also gives you a good idea of whether the creators of the toolkit in question put much priority on "playing nicely with others."