AFAIK, DDE is Windows solely and you can use it to talk to other Windows programs that support it. Some 20 years ago I wrote an ABL ( or 4GL as it was called back then ) procedure that talked to MS Word ( don't know which version it was back then ) via DDE in some Progress V8.2.
If my memory servers me right there were a lot of issues:
- First and foremost, at least at that time, it was shaky
- Secondly, the DDE recipient ( MS Word ) must have alread been launched upfront
- And, there was no way to prevent the user from closing the DDE Server ( visible in the task bar at least ) in between
Therefore, back then, I opted to use OCX integration instead as it offered far more control about the application ( MS Word ).
IMHO of course, OCX is hardly relevant today - is DDE still relevant these days?
Heavy Regards, RealHeavyDude.