Acronym for Dynamic Data Exchange, an interprocess communication (IPC) system built into the Macintosh, Windows, and OS/2 operating systems. DDE enables two running applications to share the same data. For example, DDE makes it possible to insert a spreadsheet chart into a document created with a word processor. Whenever the spreadsheet data changes, the chart in the document changes accordingly.
Although the DDE mechanism is still used by many applications, it is being supplanted by OLE, which provides greater control over shared data.