Brief history of Microsoft Outlook:

Microsoft Outlook or Outlook (full name Microsoft Office Outlook since Outlook 2003)
is a personal information manager from Microsoft, and is part of the Microsoft Office
suite. Although often used mainly as an e-mail application, it also provides a
calendar, task and contact management, note taking, a journal and web browsing.
It can be used as a stand-alone application, but can also operate in conjunction
with Microsoft Exchange Server and Microsoft Office SharePoint Server to provide
enhanced functions for multiple users in an organization, such as shared mailboxes
and calendars, Exchange public folders, Sharepoint lists and meeting time allocation.

Business Contact Manager for Microsoft Outlook

To quote Microsoft:
‘If you are in the business of selling for a small-sized to mid-sized company, whether
one product or hundreds, keeping track of your sales leads, customers, contacts, and
products is an important key to being successful. Wouldn't it be great if you could
integrate all of those tasks and the information that goes along with them into Outlook?
That's exactly what Business Contact Manager can do for you.’

Outlook  lets you manage contacts, e-mail, a calendar, and tasks. Business Contact
Manager extends those capabilities to add accounts, business contacts, and business
opportunities (such as sales) to your Outlook data. This means that Business Contact
Manager gives you the means to easily integrate all information about a customer
account in one place.  Business Contact Manager enables you to keep track of sales
opportunities and the product information associated with those sales from
initial contact through after-sale customer support through managing ‘opportunities’.
Needless to say, BCM includes a full suite of reporting capabilities.
It uses the Microsoft SQL Server Desktop Engine (MSDE), a run-time database engine
that provides the core features of SQL Server without the expense or installation
of SQL Server. Business Contact Manager Setup installs its own copy of MSDE,
even if you have an existing installation already on the computer. If you remove
Business Contact Manager, Setup removes this copy of MSDE as well, but leaves alone
any other versions installed on the computer. So BCM includes everything you need
right out of the box.

But beware - there are a couple of other points you should understand before taking
the BCM plunge:
You can't include BCM in the same Outlook e-mail profile as your Exchange Server mailbox. 
However, you can create a second Outlook profile for BCM and easily switch between
the two when you need to work with either your Exchange Server mailbox or your
BCM data. Although BCM won't synchronize your contact or e-mail information between
the two profiles, you can use Outlook's Import/Export features to move items between
the two profiles.
BCM is designed as a single-user product. 
You can't directly share a single BCM database between multiple users. However, you
can export the data from a database, and other users can use that database as the
starting point for their own BCM setup. Look for multiple-user support to be added in
a future version of BCM.

Versions, licensing and availability: 

Business Contact Manager for Outlook 2007 is included with the stand-alone edition
of Microsoft Office Outlook 2007 with Business Contact Manager and with the following
2007 Microsoft Office suites: Microsoft Office Professional 2007, Microsoft Office Small
Business 2007, Microsoft Office Ultimate 2007.

There is also a 2003 version sold as part of the Office 2003 suite Microsoft Office.
 
Outlook 2007 with Business Contact Manager is available separately.
It can be purchased and downloaded from the Microsoft Store UK.