I cant find any reference which explains how Add-ins, Plug-ins and Extensions differ from one other. I just cant accept them to be synonyms.

Here is an account of how I interpret each one. Please correct me or point me to appropriate source.

Add-ins
I guess add-ins are those modules which bring ...

Last week some one tried to make a joke about usage of Net DDE in WW products. Actually I was also not so convinced why WW still supports DDE and SuiteLink (DDE+ avatar). Since then I was trying to collect some information to educate myself on DDE.

I have been using DDE since 1998. Then I used it to create some custom report formats for customers. I used to c ...