Apple rolled out iOS 8 today, and at least a couple of vendors hailed its new file sharing features. So far, Microsoft isn’t one of them.

Not surprisingly, one of the enthusiastic vendors was Apple itself. The new iCloud Drive is part of iOS 8, and it’s ready for use. Whether it lives up to Apple’s claims about it, however, remains to be seen. Apple’s pitch for iCloud Drive starts off, “Now you have the freedom to work with the document of your choice on the device of your choice. Because with iCloud Drive, you can safely store all your presentations, spreadsheets, PDFs, images, and any other kind of document in iCloud and access them from your iPhone, iPad, iPod touch, Mac, or PC.”

Apple is now solidly into the file sharing and synchronization business. When OS X Yosemite comes out later this fall, documents will be able to be stored in iCloud and synced across iOS 8 devices, Macs and PCs. The files will also be able to be accessed from some browsers, at this point not including Firefox. But there is a catch. While you may be able to work with the document of your choice on the device of your choice, you may not be able to use the application of your choice. Third-party vendors have to make their apps iCloud Drive compatible, and today the only ones I personally could make work were Apple’s own apps: Keynote, Numbers and Pages. It certainly wasn’t possible to save files from Office for iPad to iCloud Drive.

The other vendor to hail iOS 8’s file sharing capabilities was Box. In a blog post, Box co-founder and CEO Aaron Levie hailed Apple’s new App Extensions, one of which makes it possible for app vendors to access content from other vendors and save it back to them, using standard features of iOS instead of custom development for each pair of apps. Thus, for example, I was able today to open a Word document from the iPad Box app in Pages and edit it there. When I was done, I easily saved it back directly from Pages to Box. Box’ new app has the extension built in, so that other vendors can simply work on their app, knowing they can reach Box content with a standard interface.

iOS 8 File Sharing and Microsoft

Therein, however, lies the rub. Microsoft, for example, has not announced that it has such an effort in development. Its Office 365 Roadmap keeps track of these things, including improvements to Office for iPad, and there is no mention of work on such an extension, sometimes called the Document Provider. This doesn’t mean Microsoft may not be considering it, of course, but there are reasons they may not want to.

The way it works now for Office for iPad is that it’s fairly easy to open documents from a lot of sources in the Office for iPad apps. The way you do this is to use the sharing extension in the source app, such as Box, to send the document to an Office app, which will then open the document. The problem is that there is no simple way to save the edited document back into the source app. Office for iPad only saves directly to iPad, OneDrive, OneDrive for Business and SharePoint. It’s conceivable that this is because Microsoft, and other vendors, would prefer to keep storage of their documents in the Office 365 cloud environment, for competitive reasons. But given how Microsoft has abandoned this approach in the PC space, where it has integrated with apps like Box Edit, this is by no means certain.

Microsoft is in fact expanding how much its OneNote iPad app can import from other sources. It’s easy now, for example to send a document from Box into a OneNote Notebook, a feature Microsoft says was part of its OneNote upgrade for iOS 8.

The first day of an operating system’s rollout is not a good time to know how things will look down the road. We can expect at least some other vendors to take advantage of iCloud Drive and Apple’s file sharing extensions over time. Competitive considerations are sure to play a part in this, but after today at least it looks like the file sharing process for iPad and iPhone is technically simpler.