Wikipedia currently lists the following "Internet test frameworks" :
* Canoo WebTest
So IeUnit has made what could be called an "exclusive" list of web test frameworks. Of course there are plenty of other "Internet test frameworks" including Watir, Sahi, WatiN and even JsUnit and QUnit (for jQuery).
By choosing IeUnit, I'm restricting myself to Internet Explorer, but that's sufficient for my purposes now. I also liked the idea that IeUnit had something that looked like a recorder to get me started. You don't want to build much with a recorder, but they get you started and can ease some frustration.
Unfortunately, I had trouble getting IeUnit's recorder (QuickFocus) to work. When I downloaded IeUnit 2.3.240 and tried QuickFocus, it would die upon launch. I finally got QuickFocus to work by downloading IeUnit 2.1.238 which runs against .Net Framework 1.1. It seems like QuickFocus in the 2.3.240 build had errors against the .Net Framework 2.0.
Anyway, even after I got QuickFocus working, I had trouble using it. The screencasts about it were helpful (checkout the source via SVN), but I couldn't get the "focus" to work. Finally, I figured out you need to activate the circular "attach/detach" button in the upper right of QuickFocus to get it to highlight text and such.
After that, you'll find QuickFocus isn't much of a recorder -- you do most of the recording! But you'll learn a few tricks with it, and should get you going.
I'll try to post updates on further experiences with IeUnit.