SoapQuest is a small game I decided to write after reading "20 Open World Games" on Gamasutra and coming across "Adventure".
It's a very simple tile-based game written in 1024 lines of Java. You can wander around the place, picking things up and using them on other things by walking into them. Day and night happen, and at night you need light sources to see properly.
Play around. Try to make: fire, soap, dinner, a house... Civilisation!
You can save the game too, and go back to it later. If you don't like what you've wrought, just delete your save.csv file.
Yet it's fully data-driven, based on a simple CSV format, and has things like wandering treants and a day/night cycle with light calculations.
I'm releasing this as open source in the hope someone will find joy in toying with it, and maybe extending it to something grander. Networking sounds like quite a fun thing to do to it.