With Flex 2, enterprises would only begin paying as they scale up their applications. "We think this really changes the game significantly in the rich Internet application space," said Jeff Whatcott, Adobe senior director of product marketing.

While the new, tiered pricing strategy might be construed as a response to the ubiquitous AJAX (Asynchronous JavaScript and XML) technique for Web development, Whatcott denied that this was the intent. But the company's pricing plan seems likely to make Flex either a more popular alternative to or more of a companion to AJAX.

With Flex 2, the company seeks to remove barriers to adoption. The Flex 2 software development kit is free; previous versions had been bundled with the US$15,000-per-CPU Flex Presentation Server 1.5.

With the new SDK, developers can build and deploy applications with no server component needed for lower level applications. "This gives developers a tremendous way to start building Flex applications without a lot of investment," Whatcott said. Currently, about 5,000 developers use Flex but Adobe wants the former Macromedia technology to grow to 1 million developers in five years.

With Flex 2, XML and Web services can be used for connecting to a server when data is accessed infrequently and payloads are small. For more advanced applications, Adobe is offering its Flex Data Services 2 Express software for linking between data and the presentation layer. The Express version gives developers the ability to deploy to single-CPU systems for free.