The Redmond, Wash., company expects to release a "developers preview" of the new operating system, code-named Longhorn, at its professional developers conference in Los Angeles. Although it won't be a full beta, or test, version, Microsoft executives have promised it will be more than just "slideware," that is, a program that exists only in concept and has not taken the form of actual software.
The company is expected to hand out a development kit that will give developers their first look at the inner workings of the much-heralded new operating system. Longhorn will usher in a raft of changes from previous versions of Windows.
In his Web log, Brad Abrams, a lead program manager involved with Microsoft's .Net initiative, said that developers will walk away with Longhorn code.
"If you are like me, you will not believe it until you see it in the bits," Abrams wrote. "Not only will you get to see some of the new look and feel (of the) stuff we are doing, but you will also get (a software development kit) and tools support for programming to the huge, new managed APIs that Longhorn offers."
APIs, or application programming interfaces, describe how developers can link hardware and applications software to the operating system. With Longhorn, Microsoft is trying to more tightly manage how programs access Windows system resources such as memory and disk access. To do that, the company is turning to a "managed API" model that will work to better insulate Windows from program crashes. The technology hasby Microsoft executives as a way to make Windows more reliable.
Microsoft also will discuss the next version of its .Net Framework, the software plumbing to run programs and Web services applications. The new version,, will allow developers to easily take advantage of Longhorn's managed APIs and security model.
As for the new user interface, it's unclear just how much of the design, code-named Aero, will be shown. Microsoft didat its Windows Hardware Engineering Conference in May. One concern is that if the look and feel is revealed too soon, it could be copied by others well before Microsoft ever ships Longhorn.
Still, some early design concepts have already found their way onto Windows enthusiast sites. Microsoft executives characterized the screenshots as samples of what the software giant has been working on, but not necessarily indicative of the latest thinking.
Ship date uncertain
A full beta of Longhorn is not expected until sometime next year, and it's unclear exactly when the final release will ship. Microsoft at first said 2004, then 2005. More recently, the company has said only that it will ship when it is ready, prompting speculation it could be as late as 2006 before it hits the mainstream market.
Microsoft has used a number of superlatives to describe the changes that will debut with Longhorn, with some calling it a "bet the company" proposition. Company CEO Steve Ballmer wrote in athat Longhorn was a big bet, "even bigger, perhaps, than the first-generation Windows release."
New file system
Longhorn: What's in store
New user interface
With the new design, code-named Aero, Microsoft is expected to continue its trend of fine-tuning users' options based on the type of file or device they are looking at.
Dubbed WinFS, the new filing system borrows relational database technology from SQL Server to make better sense of what type of information is in a particular file: photo, music, etc.
Microsoft has promised new versions of Office and many other of its software programs tied to the launch of Longhorn, an effort dubbed "integrated innovation."
New application programming interfaces will work to better insulate Windows from program crashes.
New file system
The new OS also represents a major effort in what the company is terming "integrated innovation," adding features in one Microsoft program that can be used by the software giant's other programs.
The company plans toa number of different projects with Longhorn, releasing a new version of Office, some of its server software, and a new server operating system, .
However, Microsoft's time frame for when it should be able to cash in on the bet has grown increasingly fuzzy in recent months. The company is expected to get somewhat more specific with its plans at the October event.
Microsoft will have to do more than hand out CDs and give developers a schedule, said Directions on Microsoft analyst Michael Cherry. He said the company will need to demonstrate why Longhorn is worth both the wait and the effort that developers will have to put into making their software work with its new file system and other features.
"There's a real message at the (developers conference) that I think Microsoft has to get out," Cherry said. "Longhorn means some big changes, but developers want to know, 'What are those changes, why are they really necessary, and frankly, what's in it for me?'"
The Longhorn dilemma
Cherry said it's not a bad thing that Microsoft is taking a hard look at how it can fundamentally improve its operating system. However, in characterizing Longhorn as such a big change, he said, the company faces dual risks.
In the short term, companies might put off upgrades on the promise of what Longhorn can deliver. At the same time, what is ultimately shipped could be so revolutionary that companies are hesitant to install it until it has been around for a while.
"Microsoft has a bit of a dilemma here," Cherry said.
Assuming the company can sell developers on the idea of Longhorn, the software giant also must answer more practical questions such as what tangible steps developers should be taking and where they should focus their efforts to really take advantage of the new OS.
"I think if you are a developer, what I'm looking for is where should I invest my resources," Cherry said.
One result of the long development cycle for Longhorn is that Microsoft will be called to do more with Windows XP. The company has said it plans to offer an update, Service Pack 2, around the middle of next year. However, the company plans few new features for the software.
Broader improvements are planned for the two specialized versions of XP--the Tablet PC and Media Center editions. Microsoft hopes to continue to expand the reach of those two products, both of which are in their first iteration, before the debut of Longhorn.
Despite the long lag time between OS releases, Microsoft is thus far sticking to its position that there will not need to be an interim version of Windows between now and Longhorn.
"There are no plans for any interim releases," Greg Sullivan, lead product manager for the Windows client division, said in a July interview. "There is no work (on such a release) being done."
A small amount of work, Sullivan said, is going toward the service pack. "The rest of it is focused on the next release," he said, referring to Longhorn.
Although it is possible to wait until Longhorn, Cherry said, any further delays with the operating system could force the company to rethink that strategy.
Sullivan characterized work on Longhorn as still at the stage in which developers are adding items to the feature set. He said the company hasn't reached that critical point at which it switches from adding features to excluding features that would take too long to implement.
As for the server version of Longhorn, Microsoft has said little thus far. Work on that product is seen as somewhat further behind, and a developer preview is not expected at the October event, despite the fact that Microsoft has described the product as being scheduled "in the Longhorn time frame."
While conceding that Longhorn is an ambitious venture, Sullivan said that it is made possible by Microsoft having unified the consumer and business versions of Windows with Windows XP.
Longhorn won't be the only topic on the agenda at the developers conference. Microsoft also is expected to discuss Yukon, the next version of SQL Server; "Whidbey," the next version of Microsoft's Visual Studio tools; and other development issues such as security, which likely will be high on developers' lists of concerns.
CNET News.com's Martin LaMonica contributed to this report.