You would be incorrect here....

Christof clarified one point that I could not recall, that you have to recompile in 5.0 before the class can be used in 5.0. This was the big advantage with 6.0 - that most elements remained compatable, like the DBC, classes, form. Menus are not compatible.

>Libraries are NOT compatible between 5.0 and 6.0 - you need to keep a separate set of libraries for each!
>
>>You will definitely not want to take advantage of things like Access/Assign Methods or the HyperLink Class. Although you cannot take anything for granted, I would suggest compiling a class in 6.0, and attempting to instance those classes in 5.0. Things should work fine for you..
>>
>>
>>>Can you have one class lib that is used in VFP5 and VFP6? I have recently upgraded to VFP6 and I want to begin using my custom lib in it, but I must also keep it compatible with VFP5 development for a while longer. I cannot risk incompatibility with VFP5.