Taking the next step to even the stakes in the emerging platform battle in rich Internet application development, Adobe announced this morning it would be releasing its Flex development environment for Flash applications to the open source community, through the Mozilla Foundation.

The move comes as Google and Microsoft step up their separate efforts to boost enthusiasm around Asynchronous JavaScript (AJAX). While Adobe is not typically known for being a development tools supplier, in some respects, it had nothing to lose by letting go of the reins of Flex, and certainly a lot to gain by building a broader community around Flash.

The Flex SDK was already released for free; what this move is intended to do is help coalesce a development community from outside Adobe around building Flex as a platform.

The basic purpose of Flex is to utilize the scalable vector graphics tools brought forth by Flash, to construct a rich set of controls that can be bound to Web services. So while you might hear a lot about "Flex applications," there are some variables to that: You don't develop stand-alone applications with Flex; and, as it turns out with today's Web development, you don't develop stand-alone applications with any single component anyway.

The background or infrastructural tasks, such as querying or managing databases, are handled by Web services that are constructed using languages such as Java or C#, and are often executed on the server anyway. The Web service gives the Flex application a kind of "socket" in which to place a request and obtain a response.

Unlike AJAX, which makes use of embedded JavaScript code inside an XHTML page to make on-demand changes to on-screen content, Flex code is adapted for use as an XML namespace, which Adobe calls MXML. What a standard programming language might consider as statements - terms that specify a change made to something - MXML places inside an XML tag, as though it were markup code. Arguments placed to that statement are then specified as attributes, which is a unique and perhaps slightly devious way of appropriating another language's grammar for use as one's own. But for developers, the mindset shift is plainly obvious, since every MXML instruction persistently reminds them, especially with explicit references to the mx: namespace identifier.

Think of how the Navajo Code Talkers of World War II embedded references to the enemy as references to Native American allegories, with each sentence they spoke in code. A non-Navajo translator would have to remember to translate the language plus the allegory; but a native Navajo would have no trouble making the connections.

The Mozilla Public License - not the General Public License - will be used to make the source code of the Flex environment and SDK freely available to outside programmers. By choosing the MPL, Adobe explained this morning, the company will still be able to provide both free and commercial versions of the Flex SDK, "allowing both new and existing partners and customers to choose the license terms that best suit their requirements," as Adobe's statement reads.

Beginning this summer, the next version of Flex, code-named "Moxie," will go into beta. Developers will find daily builds and a public bug database on Adobe's Web site, prior to the version's final public release sometime during the second half of this year, according to Adobe.