I do not have the step-by-step instructions at hand. The Delphi support has been verified a long time ago, and I do not have them installed currently.
In general, Delphi will use the COM component of QuickOPC. As such, the developer needs to reference the component first. There is a command in the IDE that allows him to view the available type libraries, and there will be one for EasyOPC - same list as in VB6, for example. If I remember well, by referencing the type library in this way, Delphi will generate the EasyOpcLib_TLB.* files for him.
If this hint does not help, let me know, I will re-install Delphi and put together the instructions. [...]
Note that C. recently had a customer who made it work with Delphi, too.