The primary function of DDE is to allow Windows applications to share data. For example, a cell in Microsoft Excel could be linked to a value in another application and when the value changed, it would be automatically updated in the Excel spreadsheet. The data communication was established by a simple, three-segment model. Each program was known to DDE by its "application" name. Each application could further organize information by groups known as "topic" and each topic could serve up individual pieces of data as an "item". For example, if a user wanted to pull a value from Microsoft Excel which was contained in a spreadsheet called "Book1.xls" in the cell in the first row and first column, the application would be "Excel", the topic "Book1.xls" and the item "r1c1".
Note: In DDE, the application, topic and item are not case-sensitive.
A common use of DDE was for custom-developed applications to control off-the-shelf software. For example, a custom in-house application might use DDE to open a Microsoft Excel spreadsheet and fill it with data, by opening a DDE conversation with Excel and sending it DDE commands. Today, however, one could also use the Excel object model with OLE Automation (part of COM).
While newer technologies like COM offer features DDE doesn't have, there are also issues with regard to configuration that can make COM more difficult to use than DDE.
DDESHARE.EXE (DDE Share Manager)
NDDEAPIR.EXE (NDDEAPI Server Side)
NDDENB32.DLL (Network DDE NetBIOS Interface)
NETDDE.EXE (Network DDE - DDE Communication)
Microsoft licensed a basic (NetBIOS Frames protocol only) version of the product for inclusion in various versions of Windows from Windows for Workgroups to Windows XP. In addition, Wonderware also sold an enhanced version of NetDDE to their own customers that included support for TCP/IP. The technology is extensively used in the SCADA field. Basic Windows applications using NetDDE are Clipbook Viewer, WinChat and Microsoft Hearts.
NetDDE was still included with Windows Server 2003 and Windows XP Service Pack 2, although it was disabled by default. It has been removed entirely in Windows Vista. However, this will not prevent existing versions of NetDDE from being installed and functioning on later versions of Windows.
Labtech packages support DDE. (dynamic data exchange) (Laboratory Technologies Corp.'s Labtech Notebook, Labtech Control and Real-time Vision)(Products and Careers Edition)
Jan 28, 1993; Dynamic Data Exchange brings real time to Windows Laboratory Technologies Corp recently announced support for Dynamic Data...
AceFile DBMS supports Microsoft Windows, DDE. (Dynamic Data Exchange) (New Products: Microcomputer) (product announcement)
Oct 01, 1991; AceFile, a database management system for the Microsoft Windows 3.0 environment, is available from Ace Software Corp., San Jose,...
MathType for Windows features DDE link. (Software Review) (Dynamic Data Exchange)(equation writer from Design Science Inc.) (Evaluation)
Jun 01, 1992; Math Type for Windows 1.1 is an equation editor designed for scientists, engineers, teachers, students, and other who need to...