Evver Games is the open source project that powers games you find here on Evver.com.  It provides an easy to use architecture, which is geared for the creation of multi-user card games.  

Features of the project include:

 The current version features:

• A web interface, written with Echo2 - a swing like API
• Supports remote clients, using Cajo, for peer to peer games

Development version features:

• A web interface written with Flex 3
• Support for remote clients using BlazeDS 

Getting started is easy, and will only take a few minutes.  Seriously!  The best way to get started is to take a minute or two and play a game.  Doesn't sound that bad, does it?  Go, take a little time and have fun.  It will help you more than anything else.

Now that you have seen a game in action, the best thing to do is get familiar with the code.   You will find that Evver Games is broken into multiple distinct projects.  The base project is the card platform.  This is all the boiler plate code that takes care of messaging, network connections, simple game logic, etc...  The web interface is implemented using Echo2, a Swing like API for creating rich web applications.  Yes, these applications are the AJAX type -- so we are buzz word compliant.  The final piece to look at is the game implementation.  For the Golf game, this consists of a handful of classes that define the game specific logic, graphics, etc...  This is the best place to start.  I would take a close look at GolfControl -- the object which handles nearly the entire flow of the game.

Once you get started, please feel free to ask any questions on the SourceForge developer forums.