Will Russian hackers be first to play with a Google Cardboard lookalike from Microsoft

Or rather, it was, until excitement about an image on a webpage promoting a hackathon in Moscow prompted the company to take the site down.

Before it disappeared, the Microsoft site invited developers to head to the Steel hacker space in Moscow on Oct. 17 and 18 to enter a competition creating educational and corporate apps and games using something called VR-kit.

It's unclear from the site whether VR-kit is software or cardwear.

According to the site, hackathon participants were to have access to software tools and code templates, and the opportunity to present their ideas to experts.

Those with successful ideas, the site said, were to be given a set of "Cardboard" -- the only word on the site in English, the rest being in Russian -- that they would be able to use for testing their app.

Images on the site of people wearing a brightly colored box holding a phone before their eyes prompted intense speculation that Microsoft is launching a competitor to Google Cardboard.

The box pictured on the event website has top and bottom edges contoured to hold a smartphone in front of the wearer's face, and a slot out of which a phone's camera peeks. The images show the box holding a phone resembling the Microsoft Lumia 930, a high-end model with a 5-inch, full HD display and a 20-megapixel Pureview camera with Carl Zeiss lens.

The company had put a lot of effort into the pages, which featured a clickable code sample allowing the viewer to project two headset-wearers into different virtual realities, "quest," "zombies" and "horror."

Make what you will of the site's disappearance: The company has a much higher profile event scheduled for Oct. 6, almost two weeks earlier, at which it is expected to launch new high-end Lumia phones, the 950 and 950XL, and also the Surface 4 tablet. The choice of imagery for the hackathon could be unfortunate timing, or a leak.

Even if Microsoft doesn't plan to overturn the VR market with the release of a new SDK or a new cardboard prototyping tool, there will be other signs of upheaval at the Moscow event. One of the partners at the event, the site said, is Fibrum, the Russian developer of a less flimsy contraption for turning smartphones into VR headsets. Fibrum also offers a VR SDK for developers of Android games, which it sells in its own app store.

Fibrum's business model may have just taken a hit, as last week the world's largest Android phone vendor, Samsung Electronics, launched a VR headset that works with all its 2015 smartphone range. The headset contains a dedicated VR display and, crucially, costs just US$99. That's less than Fibrum charges for a chunk of plastic that merely holds the smartphone you already own in front of your eyes.

Holders like Fibrum's, Google Cardboard -- or Microsoft's, if it exists, are still a great way for developers to virtually dip a toe in the water, as they have the distinct advantage of being entirely cross-platform: Any phone that will fit in the box can be used.

It's noteworthy that Microsoft, in promoting the Moscow hackathon, gave as much weight to educational and enterprise apps as to games: Back in the real world of VR contraptions Microsoft is developing, the enterprise could be a big market for Hololens, with potential applications in design, training and conferencing.