Can anything truly be said to be free when opportunity costs, not to mention the burden of the material on one's immortal soul, are considered? As Socrates might have said...
Ummm, what I meant is that there are free and commercial versions, and the free version may be downloaded at http://www.panicware.com/product_psfree.html
Yeah, that's the ticket...
P.S. In the strict mode, it blocks pretty much everything. You have to temporarily disable it if you want to let something open a new window via a javascript, and reenable it afterwards, but that's one click each.