A week ago, word leaked that Microsoft was preparing to release free versions of OneNote for Mac and for the Windows desktop. On March 17, Microsoft delivered both versions of its electronic note-taking and organizational application.

Microsoft is broadening OneNote's platform support so as to better compete with rivals, especially Evernote, on the note-taking/organizational front.

OneNote for Mac is available for download from the Mac App Store as of today. It's the first time OneNote has been available for the Mac. Previously, OneNote was available for Windows, Windows 8, Windows Phone, iPad, iPhone, Android tablets, Android phones and the Web (OneNote Online, formerly known as OneNote Web App). Mac users should be aware OneNote for Mac automatically syncs to Microsoft's OneDrive cloud-storage service.

A free version of OneNote for the Windows desktop also is available for download from OneNote.com as of today. Previously, Microsoft made free versions of OneNote available for Windows 8 , Windows Phone and the Web. But until today, users of older versions of Windows had to pay for the OneNote app as part of Microsoft's Office suite.

The new free version of OneNote for the Windows desktop doesn't include all the features in the paid version. It doesn't have SharePoint support, version history or Outlook integration. To get those features, users need to upgrade to the paid version. It's also worth noting that the free version is ad-free, not a temporary trial version, and limited to home/school use only.

Microsoft also announced that it has opened up the OneNote service -- available at OneNote.com -- to third-party developers by making available a cloud programming interface to which applications can be connected. New features available via the OneNote service include OneNote Clipper, which allows users to save Web pages to OneNote; a new me@onenote.com e-mail feature for sending notes to OneNote; and Office Lens, Microsoft's optical-character-recognition technology for capturing documents and whiteboards with Windows Phone and saving them to OneNote.

Microsoft is working on a new, updated version of OneNote for Windows 8 that will be part of its "Gemini" suite of apps . The company also is expected to deliver an updated version of OneNote for the iPad as part of its release of Office for the iPad, which is expected to arrive any time now .