The year in tech: 2016's 10 greatest wins, milestones, and epic comebacks

AI was a major theme in 2016, with tech giants like Google, Microsoft, Apple, and Amazon all touting their machine-learning chops and virtual-assistant skills. But nothing underscored the coming AI invasion like DeepMind's AlphaGo, which has become so skilled at the strategy board game Go that it trounced world champion Lee Se-dol four games to one. Researchers have long viewed Go--with 361 potential moves on the first turn alone--as the ultimate AI challenge, yet Lee said AlphaGo's decisive victory left him feeling "powerless."