By graduating, they are considered full-fledged businesses and will be part of Alphabet's "other bets," aside from the company's main cash cow, Google. They join companies like smart-thermostat maker Nest, health-data firm Verily and self-driving car company Waymo.
Astro Teller, X's captain of moonshots, says on a blog that the two companies now "seem a long way from crazy" after having started as X projects several years ago. Loon, for instance, provided internet service from the stratosphere to Puerto Rico after Hurricane Maria devastated the island last year.
This story has been corrected to indicate that Loon's devices are high-altitude balloons, not hot-air balloons.