Event Horizon is a play-by-web proto-4X strategy game written by Nick Dumas using his Ham & Eggs turn based strategy engine. I've written a user interface for the game (with some help on the graphics from a third party known as se5a).
The goal of Event Horizon is to wipe out all the enemy spaceships, as is the custom in such games, and to do so you must build mining ships to accumulate resources and warships to defend your turf and attack the enemy.
The UI is written in C# and uses WPF, so you'll need the .NET Framework to run it.
Download the UI here; I'll put up some screenshots eventually...