It's online, it's collaborative, it doesn't need registration.
I have a feeling you may be hard pushed to find an online doc collaboration tool that doesn't require registration, sorry. Registration is required so that people could have accounts, so that the accounts can be assigned to the documents being shared and edited - otherwise it could be a big mash of many documents being edited by anyone, or no collaboration :) Unless of course I completely have the wrong end of the stick here - do you mean on an intranet or something maybe?
I have found the Mayo Clinic's website to be very useful for research into health subjects. They are largely free of bias and unhelpful information.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.