Altera Terra (Latin for "another world") is a Civ-like turn-based strategy game. It is completely written in Java (using Swing as the GUI). One of the major design concepts is to provide easy access to most of the game mechanisms, so it can be modded and extended. This refers to "light" changes such as adding new units (either using XML or Java), but also to "heavy" changes like tampering with the combat rules or actions during roundup.
There are several reasons for that:
I have started coding a couple of weeks ago and just released the very first alpha version (there's just a map you can move about).
Feel free to take a look at the Screenshots.
Unfortunately, I don't have much time to actually do the coding - but there are lots of ideas in my head. I tried to put many of them in the Release Plan. So just take a look at what is going to happen in the future. I'd be happy, if you'd come back every now and then to check how far AlteraTerra has progressed.
If you'd like to get in touch, send me an email to email@example.com.