Pitch-tracking software

Hello all.
I'm wondering about other people's experience with pitch-tracking
software. For example, Wildcat Canyon claims that their Autoscore Pro 2.0
package is able to track pitch-bend. How accurate is it?
Also, there are a couple of Mac programs that track pitch. Some of them
are not that bad. And some people have interesting ideas such as
VocalLab, a pitch-training program that displays variation to 12ET notes.

>The section on Continued fractions is fascinating,but I don't quite get
>it.

I haven't seen this web page, and I don't claim to know continued
fractions all that well myself. But I think it's a means of finding
low-number-ratio approximations for arbitrary (real) numbers.