Google has begun shipping its Google Glass "wearable computing" devices to its first users outside the company – and released guides so developers can write software for it.
But one thing developers have been told is banned: showing advertising to wearers.
Although almost all of Google's revenue – and more than 98% of its profits – comes from advertising, the company is initially shying away from showing adverts on the device, which has an embedded screen in the upper-right-hand corner of the right-hand lens that the company says provides resolution which is "the equivalent of a 25in high definition screen from eight feet away."
The voice-controlled Google Glass is able to display information in the screen from the internet via a wireless connection to a smartphone, but also to take pictures and video using a front-facing camera.
According to the details provided, the camera has a five-megapixel resolution, while videos will be 720p HD resolution. Audio feedback comes from a "bone conduction transducer" which rests on the ear and uses the sound-transmitting properties of the bone around the ear to improve sound.
Google is promising that the battery should last for "one full day of typical use" – though it adds that features such as video recording and "Hangouts" (where users join shared video chatrooms) will use up more battery.