IE plug-in

Hi all, I'm looking at writing a plug in for microsoft internet explorer.
but I can't find any documentation for doing so in vb.net
so the questions are: is it possible to write an IE plug in in vb.net?
where is documentation on it? and of course documentation on installing it.
Why? I want to write a password plug in like Roboform for the most part as an educational project
second as pasword manager I can use myself... :)