DDE: Microsoft Dynamic Data Exchange

• Older mechanism for exchanging data and messages between Windows applications, still part of Win32.
• Here's what you do with DDE:
  • Establish permanent and intelligent links between two applications regarding one or more specific data items.
  • Maintain links between applications programatically.
  • Execute commands in a remote application where either the remote or supporting program doesn't support OLE Automation.
• DDE is an asynchronous protocol.
• How does DDE relate to OLE?
• DDE is the original interprocess communication mechanism, and OLE is the new one. OLE 2.0 is actually faster, according to tests in "The Underground Guide". OLE 1.0 was built on top of DDE, but OLE 2.0 is not.
• The Underground Guide to Microsoft Office, OLE, and VBA says: DDE was the first interprocess communication service provided in Windows. In 1988 a couple of PC industry firms wanted to extend DDE. By the time the dust settled, the contributers to what was called the "extensible Compound Document Architecture" (eCDA) specification included folks from Aldus, Borland, Iris, Lotus, Metaphore, Micrografx, Microsoft Application Architecture and PowerPoint Product groups, Samna, and WordPerfect. Microsoft announced the final eCDA specification at Comdex in November of 1990 and christened it Object Linking and Embedding, Version 1. The formal spec was dated December 10, 1990. The OLE 2 spec was developed with input from developers, it was ultimately manifested in the host of Office 4, which was released in dribs and drabs in late 1993 and early 1994.
• The "eCDA" acronym with the lower case "e" for "extensible" reminds me of the same "e" in NeWS!