Microsoft is releasing on Wednesday a technology preview of its Volta Web developer toolset, which is intended to make it easier to build multitier Web applications, including applications useful in SaaS (software as a service) environments.

With Volta, developers can use C#, Visual Basic, IronPython, or other .Net languages that utilize .Net libraries and tools, Microsoft said. But taking advantage of Volta requires the newly released Microsoft Visual Studio 2008 toolset because Volta will not work with the earlier Visual Studio 2005 release, said Alex Daley, group product manager for Microsoft Live Labs, which is helping to develop Volta.

The preview is accessible on Microsoft Live Labs' Web page. With Volta, developers do not have to tailor the application specifically for the Web, said Daley.

"What we're trying to do is make it easier to build Web applications by allowing programmers to focus on what they want to do and automating the how," said Eric Meijer, principal architect for Volta.

Developers prototype the application first as an entirely client application and then use a method called declarative tier-splitting, which allows developers to specify which parts of a program run on the server tier and which parts run on the client tier with a simple, declarative markup, said Daley.

Afterward, the compiler takes care of the client code, server code, and boilerplate code that ties the two tiers, handling such functions as communication, serialization, and security.

[ For more perspective on Volta, see Martin Heller's blog. ]

"At the end of the day, Volta is the framework that builds the apps so that you can have both the client and server together," said Daley.

A software developer doing a competitive analysis of next-generation Web platforms and tooling found Volta useful for developing software to run "in the cloud."

"The primary benefits for Microsoft developers is that they can use familiar tools to develop software that runs in the cloud and hence isn't hostage to the Microsoft run time," said the developer Dave Thomas, founder and chairman of Bedarra Research Labs. "It addresses one of the major problems of Web 2.0, which is development tooling."

"Unlike Silverlight, Volta has a small footprint and only depends on a good JavaScript virtual machine," Thomas said.

Volta will only work with Visual Studio 2008 because it is just built to work with the .Net Framework 3.5 right now, which is offered as part of Visual Studio 2008, Daley said.

Volta furthers Microsoft's software plus services efforts, including SaaS, because it enables easier development of multitier applications, the company said. Volta takes advantage of technologies such as Microsoft's LINQ (Language Integrated Query) and AJAX (Asynchronous JavaScript and XML) and automates certain low-level aspects of distributing applications across multiple tiers. Developers can instead focus on distinguishing features of an application.

End-to-end debugging and performance profiling are featured as well. Volta measures the speed and performance of an application to see how it performs on the client and server. Fine-tuned adjustments are enabled, such as moving a piece of code from the client to the server late in the development process.

The secret sauce, so to speak, of Volta is its use of MSIL (Microsoft Intermediate Language), which is the language used to compile applications written in .Net languages. The MSIL-to-MISL rewriting technique employed in Volta takes post-compilation steps to rewrite client IL to run in JavaScript and rewrite server IL to run on ASP.Net. Web services are generated when IL is rewritten to ASP.Net.

Developers can postpone irreversible design decisions until the last responsible moment, thus making it faster and cheaper to change an architecture, Microsoft said.

Volta's multiple language support and declarative tier-splitting make it unique, Daley said. But the technology still is in its early stages of development. The company does not have a set road map yet for when Volta will be offered as a general-release product, but periodic updates are planned for release during the development phase.

"The goal is ultimately to work with our customers as we develop the technology," said Daley.