So far I have focused on the GDK option of developing Glass apps, or Glassware. A second option, which is simpler and was offered earlier than the GDK option, is the Mirror API, which lets you use any web programming language, such as Java, PHP, Python, Ruby, .NET, or Go, to build web services that interact with Glass via Google’s cloud-based API. With the Mirror API, you can build a Glass app that publishes content to users’ Glass in a simple and elegant way. For more information on which option to use, check out Google’s documentation at https://developers.google.com/glass/develop/overview , which also briefly covers the hybrid way to build Glass apps. Basically, a Mirror API app can launch a GDK app through a menu item on a static card inserted by the Mirror app.