Winter!: Prepare for holiday gaming!
This is the oldest version of online play for Magic the Gathering that I am aware of. Few people still use it, because there are newer and flashier ways to play this game now. It's still more than good enough and barely uses any bandwidth, plus you can easily add your own custom cards. (Just don't use custom cards unless your opponent agrees beforehand.) Best of all, it's freeware.
Game Traits applied to Apprentice (PC) by LordXenophon