Embed Delphi window in another Delphi application

I have a frame in a Delphi 2007 application that I want to embed on a form in a Delphi 2010 application. I h开发者_C百科ave control over both applications, so the interface between them can be anything both versions support. There will have to be some communication between the two. The two approaches I can think of are using CreateParented and messages, or using an ActiveForm. I don't have any experience with creating ActiveX controls or out of process servers, but I've heard Delphi makes it pretty easy.

Is one method better than the other, either in terms of easy of use or ease of development? Are there other alternatives? Any gotchas I should watch out for?

The ActiveX way seems to be simplest if you want to keep your frame a D2007 one but embed it as an already compiled object in a D2010 application.