As a recognized public utility already, Verizon may be one of the best suited organizations on the planet to provide a monthly billable service to businesses, that just happens to include computing. That's the basis of the US' number one carrier's announcement yesterday. But what is it that Verizon plans to sell? With something as nebulous as cloud computing, it's often difficult to determine just what it is that a service provider is actually offering, and whether it's on a par with competitive brands. And like much of its competition, Verizon "buries its lead" with paragraphs and paragraphs of introduction about how big the cloud is these days, and how competitive business is these days, and how crappy the economy is these days.

What's the news in all of this? A company that already has a huge connectivity infrastructure is leveraging it to deliver a service for businesses to offload not only their applications, but the administrative responsibility for those apps as well, to Verizon for a monthly fee.

So we can make sense of this, here's a recap of the major players at this point, and how their cloud services differ -- and the differences are actually quite pronounced: IBM is probably the earliest player, having developed "grid" computing concepts long before someone coined the alternative term "cloud." It sells a hosting service for business applications, and offers middleware packages to go with them to promote collaboration and productivity. And it makes the tools for managing that system available to customers (and here's a key distinction).

Salesforce.com found more success than anyone ever predicted, but its "Platform-as-a-Service" (you see a theme developing here) was devised to let customers build all-new cloud-oriented applications around its own CRM databases. Meanwhile, Amazon -- which probably has had the most success in getting small business energized about the cloud -- essentially provides a well-managed hosting service for businesses to run Linux or Windows Server 2003 in the EC3 cloud for what's currently considered to be a very low fee.

Enter Microsoft, which has yet another novel approach: Windows Azure is essentially .NET Services running on its own cloud, so that whatever distributed .NET apps a developer could deploy locally can be moved into the Azure cloud without alteration, or at least not significantly.

Verizon's move today finds an approach that's somewhere in-between IBM and Salesforce. Its CaaS won't be a development platform; unlike Salesforce, CaaS will not be a kind of open API for specific cloud applications. But Verizon will make application hosting resources and storage services available on a sort of a la carte basis. And in a pricing plan that sounds very much like a Verizon plan, basic service will be available for a flat fee of $250 per month, with extras tacked on as needed.

And like IBM, Verizon will offer its business customers a front end for provisioning and deployment. "Customers have access to a real-time, self-service portal that lets them dynamically provision and manage physical and virtual servers, network devices, storage, and backup services," reads yesterday's statement. "The portal is accessed through the Verizon Enterprise Center, a one-stop resource for customers to manage all of their Verizon services."

But unlike IBM and more like Amazon, Verizon's choices do not appear to be brand-specific at present, especially in the OS department. Customers' choices of operating systems will for now include Windows Server 2003 and Red Hat Enterprise Linux, and virtualization will be made available through VMware. However, customers may request that certain applications be hosted on physical rather than virtual servers, presumably for a premium.

Verizon's key selling point here is an analog for "It's the Network," which has worked so well with its Wireless business: Verizon's admins will maintain not only uptime, but also the applications themselves, in service tiers that will be explicitly spelled out for customers. The CaaS service is available now in the US and Europe, with rollouts to Asia-Pacific in August.