Microsoft has announced that the next version of Office (unofficially "Office 12") will deliver support for a new set of XML file formats. Calling them "the Microsoft Office Open XML Formats", Microsoft wants to produce a more compact, simpler format that is more easily programmable, more reliable, and more secure.

The skeptic is going to look at this and have a few comments:

  1. Open!?  Ha! that's funny!  You Microsoft guys are always kidding around!  
  2. See?  I told you Microsoft would change the format. This is the problem with vendor-controlled formats:  Microsoft can make changes whenever it wants.  Anyone who bet on the current XML formats supported in Office 2003 is now seeing their work disrupted. And, it will force everyone to upgrade to the latest version of Office !

I can see the reason for the skepticism.  Let me comment a bit.  

"Open" as it is used in this name does not mean the schema are going to be maintained by ISO, W3C, or OASIS.   It means, "based on standards that are open".   Based on XML, XML NS, W3C XML Schema, and others.  The Schema themselves will still be "owned by" Microsoft. 

The schema will be broadly accessible with a royalty-free license supporting use within any app, using any platform technology.  Just as today, Java apps can produce WordProcessingML, and PHP apps could do the same thing (sorry no example available!), the same sort of thing will be possible with the formats provided in Office 12 .

As to the second comment - about the change in the schema disrupting developers and forcing upgrades. . .  Patches will be shipped for back versions of Office, to enable them to deal with the updated XML formats. This will include Office 2000, Office XP, and Office 2003.  These patches will be free (gratis).  I am not sure if the plan is to enable these apps to produce the new formats, or only consume the new formats.  In any case there will be patches.

Likewise, O12 apps will be able to consume the older format.  By default Office 12 apps, when saving to XML, will save to the new format.

Some other details:  Powerpoint will join the ranks of the XML-enabled apps.  Cool!  Imagine the possibilities of auto-generating a powerpoint app in XML!  Also: you'll be able to set XML as the default file format in Office 12.  Nice !  So it will no longer be a "special case" - it can be your default format.  And -..... drumroll please..... the MAC version of office will also support these new formats.

Why the change?  Couple of big reasons:  the current formats are XMl-based, but they are kinda verbose for what they do.  Lots of boilerplate markup in the XML.  The new formats will simplify this.  Also, there are changes to make the formats more compact (including ZIP compression), and more robust and reliable. These changes will address some of the issues raised previously by observers such as Simon St. Laurent .

Sadly, the new formats are not available yet.

There is a channel9 video on this.

Update 1: See Brian Jones' blog entry for more info and whitepapers on the new XML formats in Office 12.
[emphasized text added 2 June 2005 10ish US Pacific Time]

Update 2: this e-week article says the XML formats will be published at TechEd.
[emphasized text added 03 June 2005 15:32 US Eastern time]