Vassal is a software game engine that allows modules to be created to allow people to to play online board games against each other. There is a Warmachine/Hordes module for Vassal, and it is very polished. The only thing you need to play are the cards for the models you are playing.
|The game board on my victory|
As you can see from the picture below, Vassal provides all the necessary resources to play the game. There is templates, counters, front-arcs, melee range. The module is very tailored to how WM/H is played. However, the module does not play the game for you. There is no built-in assistance for gameplay. Everything is done through user actions, and through chat communications. It can even be done over VOIP to make the game play feel more immersive and go faster, but spectators will be left out the of loop. Yes, you can spectate a game, and it is very easy to do such. This allows others to provide feedback on rules if necessary, as well as provides some consoling when the dice aren't going your way.
There are many resources to get going with Vassal:WM/H but I found http://vassalwmh.co.cc/ to be very helpful with a quick short start guide.
A little information about my first match on Vassal. I played a battle box game against the user "James". He played Khador, and I played Trollbloods. He said he was very new to the game, but played very well for a suspective newbie. He understood the rules pretty well, and was able to keep the game going smoothly. I could tell by playing on Vassal things are a bit more precise. Movement is calculated, but you need to keep track of how far you have gone, there is little feedback for this. Distances are drawn exactly, so there is very little measurement disputes. We ended up going back and forth in the middle of the table, with me surviving her feat, and then nearly winced by, by using the Axer and Madrak combined to take out Sorscha. I was definitely surprised I eked out a win, but I enjoyed the game thoroughly.