There's a war going on out there. It's not the war for mobile between Apple (AAPL -0.57%) and Google (GOOGL 0.35%), with everyone else launching half-hearted sallies at an occasional exposed flank. No, this war may have more far-reaching implications: It's over the delivery of your digital experience. Will the future be spread out before you in full 3-D like the iconic Star Trek holodeck, or embedded with your inner life, unique and unseen to anyone else? Let's see where the major players stand on this battlefield, and what their stances might mean for the future of computing.

Open immersion: the holodeck approach
The holodeck was one of Star Trek's favorite plot-filling devices across multiple series after its introduction in the Patrick Stewart-led Next Generation. It's easy to see why. When you can create virtually any environment, with nearly any possible cast of characters, a trek through the final frontier can easily become a musing on loyalty in the Old West, or the nature of artificial intelligence, or a way to get your favorite android to play poker with historical intellectuals -- or anything else you can imagine, really. We're nowhere near the total immersion experienced by Star Trek's characters on the matter-manipulating holodeck, but we do have the early underpinnings of immersion already in place.

Microsoft (MSFT -1.84%) has been an early proponent of the projected display, which resulted in the OmniTouch project in 2011, and, more recently, the IllumiRoom, which is the closest thing to a "holodeck" our 21st-century technology can come to Star Trek's 24th-century wizardry. Here's a video of the IllumiRoom in action:

Other tech companies are hard at work on ways to create holograms, which would help expand IllumiRoom beyond the wall and into the room itself. Hewlett-Packard (HPQ -0.25%), for example, unveiled a 3-D display technology from its HP Labs that attempts to create holograms with LCD technologies already available. It's not quite as exciting as Microsoft's project, and it appears further away from commercialization (to say nothing of video production values), but you can see a video of HP's display in action as well:

Apple has apparently been working on a less-immersive form of projection that simply links devices to a projector, for which it received a patent in 2011. Apple has the resources and the technical expertise to pursue either a room-projection or a 3-D holographic projection system -- or both. The question is: Does anyone at Apple really want to?

Inner experience: the wearable approach
If Microsoft is leading the charge on projected immersion, Google is taking the opposite path and has staked out a claim as the undisputed early leader of wearable displays with Project Glass. Google recently began accepting a small group of people into what amounts to a highly public beta test for the devices. Will their experiences look anything like this early Project Glass concept video?

Or are its first public users more likely to experience something simpler, like this next video, which provides a helpful (but not intrusive) overlay on a corner of your world?

Apple also happens to be pursuing patents for wearable head-mounted displays, but we've yet to see anything resembling a finished technology from Cupertino. Right now, everyone is clearly playing catch-up to Google in wearable displays -- but there seems to be less of an effort made to catch up here than there is to develop the inverse form of the technology, as Microsoft has done. However, one lesser-known company has built up a wearable-computing patent portfolio that might put both Apple and Google to shame. It's Luxottica (LUXTY), the world's largest eyewear manufacturer. The biggest problem on Luxottica's plate is that wearable immersion requires software as well as hardware to be effective. Google and Luxottica would be ideal partners in development: Google's got the jump on the operating-system side, but Luxottica has the cool credibility that seems to be just out of Big G's grasp.

You can read more about wearable computing, which includes devices that don't add a layer of immersion but simply enhance your life, in a technology overview I created last year: Click here to get started.

Who wins and who loses?
It's possible that we'll go through our lives in the 2020s (or even earlier) switching between room-scale projected experiences and fully immersive augmented-reality displays in our eyewear. However, there may simply not be room in most people's lives (or wallets) for a holodeck and a set of virtual-reality goggles. Either direction would be a massive leap forward in human-computer interaction, which has been circumscribed virtually since the beginning by a screen and our fingertips. Effective software operation and functional variety are likely to push us in one direction or the other, which would point to the more-portable wearable systems as the ultimate victors -- but a world in which most interaction happens remotely, the projected reality in our living room might be all we'll ever need.

What do you think? Will the future be all around us, or right in front of our faces?