For the past decade, IBM has used the alphaWorks site as a way of granting sneak previews of new software coming out its R&D labs to early adopters. But until now, to gain access to IBM’s latest pre-beta software, you had to download it.

While this approach works fine if you’re downloading bits of software like servlet engines that Java-enabled ordinary webservers, it doesn’t work well for software that requires large infrastructure, such as high-performance computing applications.

This week, IBM is rolling out the first alphaWorks code that will be hosted by IBM online.

They will include a weather forecasting tool aptly named Deep Thunder. It’s aimed, not at forecasting agencies that already have HPC infrastructures, but business customers. And, because this is the kind of app that requires serious computing infrastructure, it’s well suited for hosting.

Other offerings are more traditional developer tools. One is a visual tool for building web apps using a browser interface, where components could be dragged and dropped to develop offerings like online shopping.

Another is a web-based collaborative tool called Adieu. (If you want to know, it’s short for Ad hoc Development and Integration tool for End Users.) Besides being collaborative, Adieu is supposed to hide the complexity of mapping to back end databases, so non-programmers could create apps such as looking up stock quotes without having to know the schema of the underlying stock quotes database.

This is not a strategy to make all alphaWorks offerings hosted. But, according to Chris Spencer, emerging technologies strategist for IBM alphaWorks, on demand provides several obvious advantages.

For instance, you can update software far more rapidly when you don’t have to rely on downloads. And, since alphaWorks is intended to expose IBM software developments before they get productized, it could speed the pace by which new features are exposed and tested by early adopters.

Could this apply to some of the open source stacks that are in IBM’s software portfolio? Although nothing open source has yet been announced, Spencer said there’s no reason why it couldn’t. But, since open source involves exposing code so the community can enhance it, IBM hasn’t yet figured the mechanism for managing this in a hosted environment.

Spencer said that there would be many more offerings added to alphaWorks on demand. By year end one of them will be an enterprise mashup Wiki tool, which would support a concept first voiced last summer by IBM’s resident emerging technology executive Rod Smith.