We've been talking about the promise of Linux on the Desktop (let's call it LOTD) for almost as long as we've been talking about Linux. But while prospects are better every day, LOTD still a long way from the mainstream.

Yet every once in awhile one of the Big Boys comes along and threatens to push it there. The latest is Sun Microsystems. At Linux World Expo last month, Sun President and CEO Scott McNealy pre-announced a Sun-branded desktop Linux box due to be introduced on September 18 at the Sun Network conference in San Francisco. The announcement is still under wraps, although Don Clark of the Wall Street Journal got a look under the shroud and found what he saw compelling enough to warrant yet another Threat-to-Microsoft story. It ran Thursday on the front page of the Marketplace section, as one of the lead stories. (The link works, but a subscription may be required.)

For clues about where this thing is going to fit, here's the key paragraph from the Journal piece:

Since Sun is making a "full-fledged commitment" starting with the Sun Network show, you'd hope to see some Linux stuff in the conference program, right? But when you search the .pdf of the program, the word "Linux" fails to appear, even though Sun already has plenty of Linux-based hardware, inherited from the Cobalt acquisition.

So what is Sun up to here? We get some clues from what Scott McNealy told us at Linux World: that the company plans to use its new Linux desktops as part of its "iWork" program, in which employees no longer have personal offices or workstations, but simply use the first available cubicle (I was going to say "stall", but I'll let Scott Adams take it from here). McNealy said Sun is looking to move from 0.8 employees per office to 1.8 employees per office (suggesting a new PHB metric: EPO).

But there is a serious prevailing ethic here, and it's one where Sun may be ahead of the curve, and that's cost-cutting. The post-Enron world is all about severely bottom-line-oriented management and accounting practices, and it's a matter of time before IT honchos give Linux a second (more likely tenth or hundredth) look, and finally start making the obvious choices.

But will they go for name-brand boxes?

According to John "maddog" Hall of Linux International, the majority of the world's PCs have for years been white boxes. No-name stuff. In the Linux market the ratio is surely even more lopsided. Clearly the IT market, however, wants commodity stuff. And surely they want cheap commodity software to go with their cheap commodity hardware. The OS platform is surely going to be Linux. That leaves the question, Where will the productivity suites come from?

The leading source of that kind of suite is Sun, which surely had something large in mind when it bought StarOffice several years ago.

But Sun is a name brand hardware vendor. It's not in the white box business. Nor are any of Tux's other large corporate friends: Dell, HP and IBM. Yet if you're looking for a serious LOTD offering, the last place you'll find it is on the Web sites of those three companies.

It's even worse than it appears.

Let's say you, as an individual, want to buy a Linux desktop from one of those guys. I just went through that exercise, and here's what I found.

I had more luck with Google, searching first for "IBM NetVista Linux" and then for "HP x4000 Linux". That took care of IBM and HP. Dell was a little harder. Don Marti helpfully pointed out that their Linux desktops are filed under "Federal Government": <http://www.dell.com/us/en/fed/topics/linux_003_products.htm>

So clearly IBM and HP are offering Linux on higher-end boxes or on manageable Linux clients to be installed in massive quantities. The question is whether or not any of these Big Boys see a broader business in this commodity desktop stuff. I think the answer should be yes. But if it is, who's going to take the lead?

So far the only answer comes from the biggest retailer on the whole planet: Wal-Mart. Look up "Linux" at the Wal-Mart site and... well, nothing happens. But look up "Mandrake" and you get a page with desktops that start at $428. And here's more good news: Jeff Gerhardt of The Linux Show reported last Tuesday that some of these boxes are finding their way onto shelves at Wal-Mart stores in the U.S. If this is happens, America might actually reach parity with China, where mainstream retailers have been selling Linux-equipped desktops for some time.

Still, Wal-Mart alone can't give LOTD enough critical mass to attract lots of independent developers -- both proprietary and non-proprietary -- to the platform. For that we need front-and-center commitments to selling Linux Desktops by the Big Four: Dell, HP, IBM and Sun.

If Sun niches Linux to droneware for corporate cubicle hives, they're not going to be the first to the front. But if the company's "full-fledged commitment" is to creating real market competition for corporate Windows boxes, I think we may finally start see delivery on the LOTD promise.

I'll be talking with Sun folks over the next few days. If you want to give me some questions to ask, put them in the comments below.