Stronghold Kingdoms is a completely original MMORTS fusing the worlds of Real Time Strategy, Online gaming and Medieval warfare together. Created by Firefly Studios, the Stronghold series has flourished over the years, seeing a great change in the way we play RTS games. This is the next logical step in that long series, adding to an already legendary catalogue; the limlitless world of the Online Game.

Register at the official website to enter Alpha test and/or Beta:

Link to Official Site

Stronghold has been quoted as being a mixture of a browser and client based MMO. The ability to have both these gives the player the ability to have a much faster, real time experience with next to no issues; while at all times staying safe while enjoying the game. There is less clutter on your hard drive making for a much friendlier space saving game. A quote from Simon Bradbury of Firefly explains this better :

QUOTE:
Essentially it is a very light PC client (that will run on pretty much anything!), that works very much like a browser based game, communicating with a server over the web. The PC client enables us to be much richer graphically than a browser based game, with richer controls and better response and feedback. Basically Stronghold Kingdoms sits somewhere between ’Stronghold’ the RTS game and browser based games such as Tribal wars or Travian.

Note the video refers to the old single player version.