I have seen in several game engines before where there will be "GameObject" or some sort of base class for mostly game objects and through macros, there will be a way to register properties for the class. What I mean by properties is say for example there is a "int Height;" in the class and you write your typical get/set function. You would then register the Height property and it will some how be saved so that way in the future, your editor would be able to use this property (with having to modify the editor of course). The main idea of this because that you don't have to write specific code for every property you want to register.

My question is, how is this possible? Does anyone have any good examples or tutorials on how this is done?

I should also note that I would imagine this means having all your classes in a DLL, which I do.

http://gameangst.com/?p=107
http://nocturnal.insomniacgames.com/index.php/Reflect

Very interesting, I read the first link and I am going through the Helium code now ... is there any suggested tutorials on how to do this from scratch?