Wanted: Curve Script Examples

I've been searching the forums for examples of Curve Scripts I could use to learn how to do custom curves or curve ops, and so far have come up empty. So, I'm just putting the request out there, if anyone has Curve Scripts they'd be willing to post and share. My initial goal is to create a curve ops type of script that can provide Start, End, Minimum and Maximum sliders for Bezier and composite curves. Eventually, I'll have a day free to just experiment, but I'd like to have those four controls to start with. I can usually find formulas for different curve profiles online, but those examples are welcome too.