Sahi vs Selenium vs Watir

Updated thorough comparison of Sahi vs. Selenium

THIS IS A VERY OLD COMPARISON AND IS NOT TRUE ANYMORE Click here for the latest: Updated thorough comparison of Sahi vs. Selenium

A brief comparison. Please let me know if any information is incorrect.
Added Watir related data from Chris McMohan's comments:

Feature	Watir	Selenium	Sahi
Browser based	yes	yes	yes
Browser type independent (IE, Firefox etc)	IE & FireFox	yes	yes
Scriptable/programmable (manageable/refactorable)	yes	not natively, but using ruby	yes (uses javascript)
Recorder	yes	Only on Firefox.	yes
Object spy	no	no	yes (hovering on any element,shows its accessor)
Simultaneuos playback of multiple scripts(reduces playback time)	yes	no	yes
Multiple domain support (go from google.com to thoughtworks.com)	yes	no	yes
Frames and popup support	yes	has problems	yes
Ant support (helps continuous integration)	yes	yes	yes
Multi language (non-ascii character)support	yes		yes
HTTPS support	yes(Protocol independent)		yes
Learning curve	Learn Ruby		Recorder reduces the need to write code.TextPad Clip Libraries can be used too.
Language of scripting	Ruby - not native to the browser	Ruby - not native to the browser	Javascript - native to the browser andhence easily extendable.
Web-app independent	yes	no - needs to be deployed with app	yes
OS Independent	no	yes	yes

Comments from Chris McMohan which I have incorporated into this comparison:
Actually, Watir has
a Firefox interface (version 1.0 just released, called "FireWatir")
a Recorder
methods intended for use at the command line like "show_links" so an object spy isn't necessary
Simultaneous playback (via Ruby threads)
Frames support (really excellent frames support)
Popup support native in version 1.5 (coming soon)
Ant support (not sure what you mean, but Ruby can be integrated with CruiseControl)
non-ascii character support (via Ruby)
Learning curve: Watir *is* a DSL for scripting the IE DOM. Ruby is just a bonus. :)

THIS IS A VERY OLD COMPARISON AND IS NOT TRUE ANYMORE