What sets Konfabulator apart from other scripting applications is that it takes full advantage of today's advanced graphics. This allows Widgets to blend fluidly into your desktop without the constraints of traditional window borders. Toss in some sliding and fading, and these little guys are right at home in Windows XP and Mac OS X.
Why is this important? When Apple released Dashboard Widgets for OS X they "copied" Konfabulator. But Konfabulator worked on both Windows (XP) as well as OS X. unfortunatnly the charged US$19.95 which was very resonable but that meant : a) not trying it tto see if you liked it, b) it was not on very many desktops.
Minor update: eweeks Peter Coffee comments on : Yahoo Rewrites Script for Web's Next Act, and notes : Konfabulator acquisition moves content provider into post-browser network-service delivery. (can you say "Widgets for your Phone and / or TIVO"?)
plus : ( previously unnoticed...) the Comic history of Konfabulator, starting at Part 1