>This is a bit misleading. A class can be defined in a prg. In some cases a class can only be defined in a prg. In the case of UI classes, I see using a prg to define the class as reducing functionality.

Even when a class is defined in a prg it's still the class that can be subclassed.

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>>A class (and therefore it's methods) can be subclassed. A PRG cannot be subclassed. I don't use a single PRG as a container for multiple functions. I use a single PRG as a container of a single function. Those functions are similar to VFPs own internal functions. I also use a VCX as a container of one class. I also add very few methods to a single class. I can therefore open several things at once and multiple programmers can access many things at once too.