Ive been looking for a Microsoft Exchange alternative for linux and I have stumbled upon OpenChange...but what is it? I try googling and I can only assume that is is a "microsoft exchange alternative". Is it just for the protocols, does it have a web based client or something? Later, after I kept looking, I stumbled upon SOGo which seems to be another exchange alternative but this one points out that it has a web based ui yet, when I look at how to install it I am given the same instructions that I was given to install OpenChange. I am assuming OpenChange is the like backend of SOGo or something.

It's more like SoGo is the backend to OpenChange. SoGo provides the mail database and the web interface, while OpenChange and Samba provides the necessary Microsoft protocols.

In theory it should be possible to use other backends with OpenChange.