Delphi plugin framework

Question

I want to design Delphi plugin framework. There are three options:
1. DLL
2. BPL
3. COM interface

Every option has some disadvantage.

DLL - Promblem

Answer 1

We use DLLs, even when using only with a Delphi application. Dll forms are embedded in the main form and use Tabs instead of MDI. For DLL to work properly we also use a shared memory manager and built with runtime packages: vcl, rtl and our own package.