Not quite free, but Febo Dataform is what I've been using for years. http://home.earthlink.net/~dataform. $US 75 for 6 mo. Very easy to use ascii files that are emailed to me at the end of every trading day. Comes with a simple free charting program with a few basic indicators. It seems to be a one man operation. Hope this helps someone.
I use Pinnacle Data, US$12 per month for all the North American commodities. The advantage is that I can create back-adjusted or non-adjusted continuous files on the fly. This allows me to use long term indicators like 200-bar MAs. Downloading is a breeze. There is also a very useful table of info on rollover dates, and the number of calendar and trading days left before rollover. The drawback is that I can't check prices of the forward contract. I have to wait till the current contract expires before the continuous files splice in the new prices. This is a bit inconvenient. If I get trade signals near a rollover date, I have to look elsewhere for info on the next contract in order to enter my trades.