MTG Forge lets you play the card game Magic: The Gathering against a computer opponent using all of the rules. This is very different than playing solitare Magic with Apprentice or Magic Workstation because the AI will attack and play spells. Currently there are over 1,600 cards ranging from old power cards like Ancestral Recall and Lightning Bolt to newer cards like planeswalkers. The user interface is basic, but it does let you download all of the cards pictures and view them while playing the game.
You can also play sealed deck, draft, or the new quest mode. In draft mode the AI drafts for the 7 other opponents and builds the decks from the cards that it chooses. In the quest mode you start out with a few cards and the more games that you play the more that you win. As you get more cards you can update and change your deck.
Download - MTG Forge uses Java and works on Windows, Mac, Linux, etc...
Tutorial (85 MB) - If you don't know how to play Magic: The Gathering download this windows demo.
MTG Forge requires Java, if your computer doesn't have Java you can get it from here, java.com/getjava