Horde3D

I see Horde3D makes extensive use of XML. Is it possible to perform all that's present in XML in plain code?

Should be. Although here and there some functionality might still be missing. Especially the FX sections of the shader files are not used to be changeable via the API. But I guess that would not make too much sense anyway (and the shaders are not XML so that does not affect your question ).

Do you miss something? Or was it just a general question?

Just a general question. I have a wish to write interface which, with the help of the bridge pattern, could use several engines. Specifying rendering commands in XML doesn't look like other engines do it.

Yeah I did this for a much earlier version of Horde3D.
I had, for example, a Pipeline class which had member functions to set all the required fields, and also had a ConvertToXML function, which I'd use to load my object into Horde.