Re: Toolkit for Borland C++
^Im not aware of the problems you were facing , but I have been using VCL with OpenGL for a good 3+ years now, on a regular basis, without trouble.
The trick is to not mix the two on the same 'window' or 'form'. That said, you can have a decent VCL tool-bar on its own window that manipulates an OpenGL drawing in another OpenGL window.
I am not sure about passing non-standard VCL data to OpenGL function calls, but standard strings should be fine. Infact, at the moment, I am passing GLSL shaders in real-time via VCL using a TMemo. I can modify the shader on the fly, and see the OpenGL scene change dynamically.