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Outlook versions and trivia

Some trivia about Outlook version numbers;
-What are the version numbers of Outlook and their released names?
-Why does it start with version 8.0?
-Why is there no version 13.0?

You can look up the version number of Outlook via Help-> About Microsoft Office Outlook.

This version number is used for stamping the installation files of Outlook and is also used in the Registry, with the most known Registry hive being;
HKEY_CURRENT_USER\Software\Microsoft\Office\<version>\Outlook

An overview of the released versions of Outlook and their version numbers;

Outlook 2013 icon
  Outlook 2013 icon

Version Name Version Number
Outlook 97 8.0
Outlook 98 8.5
Outlook 2000 9.0
Outlook XP/2002 10.0
Outlook 2003 11.0
Outlook 2007 12.0
Outlook 2010 14.0
Outlook 2013 15.0

Background info

Outlook was first introduced in Office 97 which had the version number 8.0. The version numbering of Office itself skips number 5 and 6. This is because since Office 95 (version 7.0), all Office applications started sharing the same version number. Word at the time was in its 6.0 version and with that it had the highest version number. Its next version for Office 95 would become version Word 7.0 so that version number was taken for the entire Office 95 suite.

Outlook 97 replaced the applications Schedule+ and Exchange Client which were previously bundled with respectively Office and Exchange Server.

Before Outlook 97 there were already clients called Outlook bundled with Exchange. Their names are; Outlook for MS-DOS, Outlook for Windows 3.x, and Outlook for Macintosh. After “Microsoft Outlook 2001 for Macintosh” came Entourage which offered Exchange connectivity for Mac users. All these versions have their own version numbers which have nothing to to with the current versioning scheme.

Outlook 98 was initially a free download and later remained as a free upgrade for Outlook 97 users adding new features – most notably support for non-Exchange accounts. Its availability has been pulled shortly before the release of Outlook 2000. As its release was outside the normal release cycle of the Office suites (to which the version numbers have been tied), the version number of Outlook 98 could not be a full version higher than Outlook 97.

No version 13.0

At the MVP Summit in 2009, Steve Ballmer admitted (to little surprise) that there won’t be a version 13.0 for any of the Office applications because of “plain old superstition”. However, he also said that there is no “company policy for superstition” and that other product groups may release a 13.0 version of their product in the future. Obviously this superstition isn’t going to be localized for other markets where they would fear the number 14.

Other current uses of the Outlook brand

Outlook Web App (OWA) is the Web-based e-mail interface of Microsoft Exchange Server. Initially it was called Exchange Web Connect but soon replaced with Outlook Web Access. Since Exchange 2010 it is called Outlook Web App. As it is a part of Exchange, the Outlook Team doesn’t develop it. However, the release cycle of Exchange is synchronous to the Office Suite and shares the same version number since Office 2010.

Since Office for Mac 2011, Outlook replaced Entourage but has has a completely different development team (they are even located in a different State!) and another development cycle. While it does share the same version number, usually, Office for the Mac is released 1 year after its Windows counterpart.

In August 2012, it has been announced that Outlook.com will replace Hotmail. While Outlook.com takes over some design elements of Outlook 2013 and OWA 2013, this is also managed by a completely different team. Taking Outlook.com into production is part of the “Wave 15” project which again matches the version number of the Office releases.