Need example of a good modular registration form

We are redesigning our clunky registration form and I’m looking for an example for a modern registration form that is modular? Any one know of one??

I have to wonder as to how you define modular, especially for a form.
Also I think the “form follows function” is a quote that would apply here.

It is a registration form, but how complex? how many fields? Addressed to whom?

You don’t mention what business you need this for…but you could check out some of your competitors’ forms.

I think by modular form he here mean that it have some specific fields that can be added whenever required. I mean say password filed can be in login as well as registeration form so it can server both. Here hey means we have a predefined fields which when ever we want we can add it or modify it as per the requrement without coding all again.

I mean modular is totally different in sense but what i understand i defined above.