i don't think there is anything permanently free but you can go from broker to broker trying 30 day trials on different platforms. if your really serious about trading, you should take these brokers up on these trials so you may see which trading platform you like. the last thing you want when you start trading is mistakes because trading platform mistakes are VERY expensive.
Cybertrader, J-trader, strategy runner, ninja trader, PFG futures....all offer real time quotes from CME There are tens more....... They all can offer realtime data for Paper trading, but you will feel little lag (1 second) comparing to when trading your real account.