>As Rick pointed out - the scaleability issues relate to calls to the same server (DLL) each DLL gets its own version of the runtime. Hence, another thread of execution gets spawned. Within each thread - VFP only supports 1 active apartment at a time. VB on the other hand - has the ability to process multiple apartments at a time. MTS is definitely in its infancy. For the vast majority of VFP applications written today, MTS is not a requirement and in many cases - should be avoided for the reaons Rick pointed out.

Not quite <s>... but the end result is the same.

VFP does support mulitple apartment threds just like VB does. But most likely
there's some code that at the beginning of any call into an Apartment executes
a Critcial Section to prevent any other code from accessing this same server
at the same time. VB doesn't have this blocking code - VFP does.

VB also has some limitations. It can only create a certain number of apartments
of a server and once that number's used up overlays apartments ontop of existing
threads storing and restoring the environment accordingly. Apparanetly there
have been a number of problems with this from what I've heard.

Not sure how this was addressed by VB6 though...