Continuous integration (CI) is the practice of continuously building and testing code changes as they are made, to catch and fix problems early in the development cycle. CI is an essential part of DevOps and agile software development. Popular CI tools include Jenkins, Travis CI, and CircleCI. View more Augmented reality (AR) is a technology that superimposes digital content onto the real world, using devices such as smartphones, tablets, and glasses. AR is used in many applications, such as gaming, education, and retail. Popular AR platforms include Apple ARKit, Google ARCore, and Microsoft.