CQG is a trading platform developed for more professional-level options and futures traders. The company behind the platform - CQG, Inc - has been operating in the US and European market since the 1980s, and expanded to Asia in the late 90s. The platform connects directly to more than 100 futures and stock exchanges around the world, including the CME, CBOT, LME, NYMEX, and many more.
The CQG platform is normally free in its most basic web-based version, and is available for a monthly subscription fee in more advanced versions. As a professional-level trading terminal, however, many brokers only make CQG available to their best clients. Depending on the broker, you may therefore need to fund your trading account with a significant amount of capital in order to use the platform.