Adobe may have killed the competition in online publishing by acquiring Macromedia. But Microsoft is not keeping quite. The next version of Windows will include a new document format, code-named "Metro," to print and share documents, Microsoft said Monday. Metro appears to rival Adobe's PostScript and PDF (portable document format) technologies.

The format, based on XML (extensible markup language), will be licensed royalty free and users will be able to open Metro files without a special client. In the demonstration, a Metro file was opened and printed from Internet Explorer, Microsoft's Web browser.

The Metro technology is likely to go head-to-head with Adobe's PostScript technology. "It is a potential Adobe killer," said Richard Doherty, research director with The Envisioneering Group in Seaford, New York. "But this is just the first warning shot. Adobe could put something that is even more compelling Longhorn. [Via]

This is not the first time and PDF have been in Microsoft's crosshairs. When Microsoft originally announced its Xdocs electronic form plans in 2002, Xdocs was seen as a threat to Adobe and PDF. Indeed, the InfoPath feature that was eventually added to Office is a competitor to Adobe's server-based document management tools, known as LiveCycle.

Whereas is choosing to take PDF head-on, Apple Computer took a different approach when it created Mac OS X's print format. Apple uses PDF as its native printing format and also as an option for saving any Mac OS X file. Though it uses PDF, Apple did its own implementation of the format, using the PDF details Adobe has published.

In fact, one of the things that may help Adobe is that the company is not alone in supporting PDF. Because it published the basic details of the format, it finds itself competing against other PDF creation and management products. On Monday, for example, Arts PDF announced its latest PDF product, challenging Acrobat directly with Nitro PDF a $99 product for authoring PDF files. [Via]