MagicWars has 100 cards from Zendikar as well as all 145 cards from Alara Reborn, which includes cards with cascade. Implementing a whole set, even a small one, is phenomenal. MagicWars has many decks that are currently running around in Standard such as Time Sieve, RW Reveillark, UB Faeries, and Cascade-Swans, which makes MagicWars appealing to players that want to playtest current decks.
I have previously written about why a good user interface is very important and MagicWars doesn't disappoint in this area. The user interface is very nice with pretty little icons that appear next to cards that have abilities such as flying and deathtouch. MagicWars also supports such advance features as transparent windows and changeable backgrounds.
The project is written in Java and is open source, so anyone can contribute. Nantuko84 also writes a blog.
(Warning Will Robinson, MTG Forge users should put on sunglasses before viewing screenshots with this much eye-candy.)
Screenshot 1 - game in progress
Screenshot 2 - deck editor
In order to host a game you have to manually type in your IP address. Below is taken from the wiki.
Just unpack archive and run bat file. If you need to host a server, change address in MagicWars.properties file
address=localhost to address=
and in jndi.properties (I will find out later how to set jndi on a fly from java) jnp://localhsot:1099 to jnp://your IP:1099
That's it! Have fun ;)