Microsoft started to ship a first batch of its HoloLens augmented reality headsets to select developers and enterprise partners Wednesday, just in time for its annual Built developer conference. The company is expected to send some 3,000 HoloLens pre-release development kits.

HoloLens is an augmented reality headset, meaning that it allows users to see the real world around them, while overlaying it with 3D holograms.

Microsoft used its Built keynote to highlight some of the momentum behind the still-nascent augmented reality project. “Thousands of people have experienced HoloLens over the past year,” said Microsoft technical fellow and HoloLens evangelist Alex Kipman during his keynote appearance. He added that a number of big companies have begun to work on apps for HoloLens, including Japan Airlines, Saab, Volvo, Lowe’s, Airbus as well as VW.

The company demoed HoloLens on stage with Case Western Reserve University, letting users look at a 3D hologram of an MRI scan. Another demo shown off in a video was of NASA’s Mars exploration, which included an appearance of legendary astronaut Buzz Aldrin.

Interestingly, Microsoft chose not to highlight gaming among the kinds of entertainment experiences on HoloLens. Legendary Entertainment was mentioned as one of the companies developing experiences for HoloLens, but most examples shown on stage and  as part of new promotional videos were about use cases in research and the workplace — perhaps a hint that at launch, HoloLens will be anything but cheap.

That’s also true for the pre-release dev kits that Microsoft started to ship this week: Developers who are getting first dibs on the technology had to fork over $3,000 for the headset.