Huateng "Pony" Ma (ma is horse in Chinese, hence the nickname) may be the most soft-spoken billionaire tech entrepreneur in the world. The cofounder of Tencent, Ma quietly presides over one of China’s most dynamic companies. Tencent began as a messaging service but grew into China’s dominant mobile-game maker. Games were lucrative, but Tencent’s WeChat tool—which is how Chinese people talk, message, and pay—catapulted it into the cultural stratosphere. Tencent’s growth has been phenomenal: Revenues and profits have jumped an average of 44% annually for the past three years. One challenge? The Chinese government is cracking down on the addictive nature of Tencent’s games.