Brian Jones, Program Manager for MS Word team announced the new file formats in the next Office System a.k.a Office 12.

According to him, most of the file extensions are also going to be suffixed by "X" (DOCX, PPTX, XLSX etc...)

For security reasons the Macro-Enabled file types in Office System will be treated as different file types (.xlsm)  in Office 12.

Excerpt from Brian's Blog

  1. Open Format: These formats use XML and ZIP, and they will be fully documented. Anyone will be able to get the full specs on the formats and there will be a royalty free license for anyone that wants to work with the files.
  2. Compressed: Files saved in these new XML formats are less than 50% the size of the equivalent file saved in the binary formats. This is because we take all of the XML parts that make up any given file, and then we ZIP them. We chose ZIP because it’s already widely in use today and we wanted these files to be easy to work with. (ZIP is a great container format. Of course I’m not the only one who thinks so… a number of other applications also use ZIP for their files too.)
  3. Robust: Between the usage of XML, ZIP, and good documentation the files get a lot more robust. By compartmentalizing our files into multiple parts within the ZIP, it becomes a lot less likely that an entire file will be corrupted (instead of just individual parts). The files are also a lot easier to work with, so it’s less likely that people working on the files outside of Office will cause corruptions.
  4. Backward compatible: There will be updates to Office 2000, XP, and 2003 that will allow those versions to read and write this new format. You don’t have to use the new version of Office to take advantage of these formats. (I think this is really cool. I was a big proponent of doing this work)
  5. Binary Format support: You can still use the current binary formats with the new version of Office. In fact, people can easily change to use the binary formats as the default if that’s what they’d rather do.
  6. New Extensions: The new formats will use new extensions (.docx, .pptx, .xlsx) so you can tell what format the files you are dealing with are, but to the average end user they’ll still just behave like any other Office file. Double click & it opens in the right application.

Since Office 12 is going to take us in to pure native world of XML, Horizons are almost touching sky for Developement. Certainly this is a great news for Developer Community. Office 12 is going to give ability to developers to examine the contents of the file with out writing a single line of code. They can treat these files just like any other zip file.

Download this Document which talks about the New Office XML format and Preview for Developers.

Channel 9 featured a very interesting demo of the same here