There're quite a few things that I've learned along the way - work on the game has seen my try out (and hate) Seam, has seen me tinker with and discard Eclipse, Netbeans and ultimately Java itself. Which is noteworthy mainly because part of the motivation behind this project was to learn Java. Ho hum. On the other hand, my game has definitely been raised in the C# stakes - I've moved from rather disliking the language to an appreciation that it is, in fact, fricking cool. I've learned a lot about NHibernate, which was really handy for work. Sadly, despite it proving extremely useful for non-Henge purposes it became apparent (at least to two thirds of the team) that even with NHibernate, a SQL database was forcing too many compromises on us, so we ditched it almost entirely in favour of db4o. My word, there was a decision that led to a ludicrous amount of work. On top of that, Henge has allowed me to get to know and to love git. I've moved from cvs to subversion to git over the years and each step has been a massive leap forward. As much as I've championed subversion in the past I have to say - these days, if you're not using git you're almost certainly doing versioning wrong.
And after all that - and a lot more - we still don't have a playable game. As it stands at the moment, you can create a character, walk around a map, starve to death and drown. But it's getting there. There's an awful lot of architecture in place now. Hopefully one day you'll be able to play it and see what all this effort has been for. But one of the big things this has shown me? All those one-man bands who managed to design and build their own browser game, from the sophistication of Nexus War to the simplicity of Urban Dead and even the semi-complete mess (sorry, really I am, but look at the code. It needs a rewrite!) of Shintolin... they all all managed to do an amazing thing. Getting one of these things up and running is bloody hard work. Or, at least, that has been my experience of it so far.
Hopefully I'll find the time and motivation to write a little more about the design of henge before I forget too much about it; it's already started to happen - there are things that I've had to spend a long time figuring out twice because I forgot why we did them the way we did them in the first place. If not, I hope at least to get enough working to let some people poke it with sticks until it falls over.