The hellcore is an extension and improvement to the stock LambdaMOO database. I know this forum has a few folks interested in MUD or MOO. You can get it here, thanks to the wizards at hellmoo.org:
It includes everything you need to start your own MOO with the hellcore. You need a linux machine to compile and run it. It does not include any HellMOO items, areas, creatures, or content (well... there might be some here and there).
My own MOO project uses this database and it might save you upwards of dozens of hours, and has many neat features. I hope this information is helpful, as I have seen many players express interest in it.