EZProRealty is only a forked version of OpenRealty. What they did was take the opensource version of OpenRealty, modify it in ways that make it better for modern real estate sites, add in several free addons you would normally have to purchase from addon vendors and completely rebuild the template structure and administrative interface.
They added in key features for working with MLS providers too including features for hotlinking MLS images.
EZProRealty plugin works with OpenRealty or EZProRealty, you can see it working with OpenRealty right here
Welcome to the Frontpage which is a temporary domain for building and testing some of the component features. They are hashing out some of the SEF URL things today and Monday but for the most part the URLs look real clean and look like
EZProRealty
My WordPress Realty plugin does the same exact thing but for WordPress and its available now. I have no documentation but I will have late next week.
~ Jared