For at least a year, we've been writing about the tight link among software as a service (SaaS), virtualization, and software appliances. All are variations on the same message: "Let us run more and more of your data center operations for you."

Now it's time to add a fourth technology to the soup: cloud computing. Of all the new ideas listed above, this may be the most interesting because it is fast becoming the next major opportunity and battleground for longtime competitors/some-time partners Cisco, Dell, EMC, Hewlett-Packard, IBM, Microsoft, and Sun.

This time, though, they will face a barrage of relative newcomers, including Amazon, Facebook, Google, and salesforce.com, in the race to be the new platform-in-the-sky for businesses and/or consumers. For an analyst, there's nothing better than tech titans battling to change the face of enterprise computing and the world of software, as we know it.

I was in San Francisco last week for the second annual Virtual Appliances Leadership Summit. VALS was sponsored by rPath, one of the leading proponents of software appliances for on-premise applications, SaaS, and cloud computing. The summit drew 100-plus attendees, with most coming from some sector of the plumbing market, including chips, operating systems, storage, computing, virtualization software, and integration products.

As I sat listening to executives from Amazon Web Services, Citrix, and EMC, it became clear that there are multiple different approaches to cloud computing. After talking with rPath CEO Billy Marshall and reading the new product announcements from IBM and Microsoft, we've identified four different types or strategies. No, I am not going to label them as cumulus, stratus, cirrus, and nimbus.

No. 1--Open cloud strategy: A good example would be Amazon Web Services. Subscribers can pay as they go for use of Amazon's S3 (Simple Storage Service), EC2 (Elastic Compute Cloud), SQS (Simple Queue Service), SDB (Simple Database Service), and other offerings.

After he was finished presenting, I asked Amazon's chief evangelist whether his company would also offer a software development kit to aid in writing applications. He said, "No. Customers are free to use whatever programming tools they want," and proceeded to rattle off a list of the most popular ones. As it turns out, a developer has already built a Google App Engine image on EC2.

No. 2--Walled garden strategy: Credit for this description goes to Mr. Marshall as it comes directly from his latest blog posting. He takes Google to task for requiring developers to "program the application in the Python implementation specified by Google and run it on a Google server" in order to take advantage of various Google offerings. Google is not alone here; he also placed Microsoft and salesforce.com in the same category.

No. 3--Internal cloud strategy: EMC's presentation confirmed that there is an opportunity to provide cloud computing for an individual enterprise. The company has appliances for storage and security, and may also have one for its Documentum product line. EMC also owns a 90% stake in VMware, the company synonymous with virtualization. It appears that EMC will provide computing and storage services for individual companies. (Note: I missed IBM's briefing on its new iDataPlex offering, which looks as though it will provide similar capabilities.)

Admittedly, this category may be an arbitrary distinction since it's too early to say whether EMC's approach will really differ from Amazon's. It may all have to do with the sales strategy and implementation, such as a single-tenant sales and implementation strategy versus Amazon's distributed multitenant approach.

No. 4--Land-and-sky strategy: Microsoft's new Live Mesh looks to provide some combination of on-premise software and SaaS/cloud services, though there are more questions than answers at this point. If you're curious, please check out Jonathan Yarmis's piece: "Microsoft Shoots for the Clouds with Live Mesh."

Do application vendors need to get their heads in the clouds?

Only a handful of application vendors and business intelligence (BI) providers attended VALS, including QAD and SAP Business Objects. The latter are rPath customers. QAD has an ERP appliance that it is testing with several large customers. Business Objects, now part of SAP, is working on a BI appliance that should ship this quarter.

It's not clear what SAP's overall strategy will be for appliances and cloud computing. Likewise, archrival Oracle has been quiet, too. I suspect that we will start to get some insight at the two spring SAPPHIRE events and Oracle OpenWorld in September

With hype building in the cloud marketplace, it is always good to remind readers of some of the challenges, too. Besides security, Sarbanes-Oxley compliance, and monitoring and management, some cloud services may suddenly disappear for a time. While reading InformationWeek's coverage of some of the news, I noticed that HP had recently suspended Upline, its new online storage offering, after less than two weeks. Likewise, Google's Gmail was down for 30 minutes earlier this month.

Still, you've got to like rPath's position. Whether you see it as an arms merchant or seeding the clouds, rPath has multiple opportunities in the continuum from software appliance to cloud. For example, in one presentation, an rPath customer described deploying his software on the rPath appliance and storing all of his data on Amazon.

Since the launch of Amazon Web Services, rPath has allowed developers to build their applications on rPath's virtual platform to create an Amazon Machine Image that runs on EC2. Developers can use VMware, Citrix XenApp, or other virtualization options. It is safe to assume that rPath is working with many of the other cloud combatants, too. All were represented at the recent VALS event.

In the meantime, what do you think? Where are you with your cloud strategy: land-locked, poised for take-off, or airborne? Which strategy would you bet on to win: open, walled garden, internal cloud, or land-and-sky?

As always, I welcome your feedback and [email protected].
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