From the site's news announcement:
The database includes the name, age, marital status, occupation and relationship to the head of household for all residents recorded within the house. Also noted are family members who had died since the last census return in 1841, along with cause of death and approximate date.
The returns available cover complete listings of households in the parishes of Aghalee, Ballinderry, Carncastle, Dunaghy, Grange of Killyglen, Kilwaughter & Larne. Some Townlands in the parishes of Aghagallon, Ahoghill, Killead, Newtowncrommelin, Rasharkin & Tickmacreevin are also included.
Townlands covered are:- Aghacarnan, Aghadavy, Aghalee, Aghalee Village, Aghanamoney, Aghanliss, Ardmore, Artnacrea, Aughnamullan, Ballinderry, Ballyboggy, Ballyclan, Ballycregagh, Ballyedward, Ballygally, Ballygawn Ballycoos, Ballygilbert, Ballyginniff, Ballyhackett, Ballyhampton, Ballyhill Lower, Ballyhill Upper, Ballykeel, Ballykelly, Ballykennedy, Ballylacky, Ballymacilhoyle, Ballymaclose, Ballymacmary, Ballymacrevan, Ballymather Lower, Ballymather Upper, Ballymullock, Ballynadrentagh, Ballynageeragh, Ballynaghten, Ballynanaghten, Ballyquillan, Ballyreagh, Ballyrobin, Ballyruther, Ballyscolly, Ballysculty, Ballytober, Ballytweedy, Ballywillan, Boltnaconnell, Boydstown, Brackenhill, British, Capanagh, Caragan, Carmavy, Carnaghliss, Carnbeg, Carncastle, Carnfunnock, Carnmore, Carrowcowan, Cloughgaldenagh, Cluntirriff, Corkermain, Craigdunloof, Craigfad, Craigfadock, Craiginorne, Craigs, Crew Park, Demesne, Derrykillultagh, Donbought, Drains, Drainsbog, Droagh, Dromain, Drumagrove, Drumanduff, Drumnadonaghy, Drumnagreagh, Dungonnell, Eglish, Evishcrow, Farnacushog, Garryduff, Glebe, Glenleslie, Gortrany, Inchamp, Irish Armberbawn, Kilcreeny, Killough, Killyglen, Killyree, Kinflea, Legagrane, Legatirriff, Linford, Lisnahay North, Lisnahay South, Lisnamanny, Loughduff, Loughrelisk, Lower Tullaketagh, Lurgansemanus, Lurganteneil, Lurgill, Magheraboy, Minnis North, Minnis South, Moneycrumog, Montiaghs, Moygarriff, Muneyduff, Old Mills Ballygally, Poobles, Portmore, Rosedermot, Saint Cumming, Sallagh, Solar, Tamnyvane, Templecormac, Tiftarney, Tiscallen, Tullaghbane, Tullyballydonnell, Tullynewey, Upper Tullaketagh.
HOWEVER...!!! Great as it is to see this included in the Emerald Ancestors subscription, it is worth knowing that much (if not all) of this information is also freely available on the Irish Genealogy on the Net website at www.irishgenealogy.net/cp/phpbb3/viewforum.php?f=34&sid=5149434fc7eefeec46e6aed783c9e7d5
Sadly, although I was born in Larne, none of my family was there in 1851! But a great resource nonetheless.