Google last week became the latest company to offer an application platform service on the Web. Google's offering doesn't have the heft for business use yet, but it's another significant indication that corporate users need to pay attention to the emerging array of basic infrastructure services being offered online, a trend increasingly being lumped together as cloud computing.

Google's Application Engine lets developers create and host Web apps that use a variety of online services, such as a distributed data store and replication and load-balancing services. Developers write applications in the popular Python language, and they can create links to other Google services, such as its authentication platform.

At least for now, Google says its Application Engine isn't ready for the enterprise. Product manager Tom Stocky says Google hasn't even approached companies with the service. However, Google likely will look toward business users in the future as the service evolves to include features such as offline processing and support for more languages.

SERVICES, STRUCTURED OR RAW
Google joins Amazon.com, Bungee Labs, Elastra, and Salesforce.com, among others, which offer platform-level services such as application development, database access and querying, storage, and even pure computing power as either bundled, structured suites of online services, or unbundled and relatively raw ones.

Even Microsoft is poised to more fully enter the market. It's testing SQL Server Data Services, a hosted data-storage and query-processing service, though it hasn't settled on a release date. In one tantalizing hint, a Microsoft job listing posted late last month referred to a utility computing platform code-named Red Dog, due within a year, that will offer an array of computation, service management, and storage services.

While these services are most often intended for consumers, startups, and small-business users, there are examples of big-business applications that show its potential. The bigger companies that do use these services tend to do so for hosting business and customer-facing apps. Nasdaq, for example, uses Amazon's S3 storage service to host data for Nasdaq Market Replay, an app that lets companies play back days- or months-old market data in real time. The Schumacher Group, an emergency medicine practice management company, uses Salesforce's Force.com application platform to host a homegrown database application that schedules physician visits to disaster zones. Other corporate scenarios include data backup and application testing.

S3's cheap scalability has garnered considerable interest from people working for Nasdaq corporate IT, says Claude Courbois, associate VP of product development for Nasdaq data products, but he isn't aware of any internal IT projects yet that use S3 or similar services. "When I tell people about it, they say, 'Wow, that's a really nice cost model,'" he says. However, there are plenty of situations where an online service is "a nonstarter" at Nasdaq, he says, particularly with transactional or highly secure data.

Companies still have "deep, dark fears" over security, says Adam Selipsky, VP of product management and developer relations for Amazon Web Services, who admits that applications that house critical data that requires low latency or falls under regulatory constraints may not be the best choice for hosting online. Some companies that use these services, like RSS aggregator NewsGator, say they're wary of service levels that don't live up to expectations. Amazon's EC2 service was down for an hour last week, and Google's Application Engine has no service agreements.

Despite the list of concerns and exceptions, both offerings and interest in cloud computing are increasing. It's unwise not to put it on watch.