Kepler Computing, a San Jose startup founded in 2018, has emerged from stealth with a novel 3D stacking architecture for high-bandwidth memory that bypasses expensive EUV lithography and can work with existing fabrication plants. The company has raised $468 million from investors including Intel Capital, AMD Ventures, and Bill Gates, plus a $245 million US Department of Commerce commitment, and is currently testing its technology in Singapore with manufacturing partner GlobalFoundries.