I think you would need COM then however it's a mess. Compile all under one version.
Cetin

>Hi,
>Hmm.. sorry, i still cant get it.
>
>Let say I have an application, myApp.exe 1.0. It is compiled using VFP8 SP1. They are more than 100 customers using it.
>
>Today, a new customer request us to customize the app. I found that the customizations required can be achieved easily using VFP9.
>
>How could I deply myApp.exe 1.0, retain compiled using VFP8SP1. And then the customization part using VFP9 runtime. How to call VFP9 written program from myApp.exe? The result from VFP9 written program must be able to returned to myApp.exe. Do I need to build them as COM?
>
>Pls advice.
>
>Thank you