Microsoft invested $1 billion in OpenAI in 2019 because it was “very worried” that Google was years ahead in scaling up its AI efforts. An internal email, titled “Thoughts on OpenAI,” between Microsoft CTO Kevin Scott, CEO Satya Nadella, and co-founder Bill Gates reveals some of the high-level discussions around an investment opportunity in the months before Microsoft revealed the partnership. Microsoft has now invested more than $13 billion in OpenAI, adding its models to Office apps, its Bing search engine, Edge, and even inside its Windows operating system. It has helped Microsoft be seen as more of a leader in AI, instead of falling behind as it once feared five years ago.