I know this is a very difficult task to describe my application but at least i can describe what is the requirement. I don't know whats broken , having issues or not fully implemented on wine. Perhaps you have a list? that would be great! -I need an access to the serial port of the computer (real-time). -The app is also an custom HTTP server using winsocks (at peak maybe 100 connections). -The apps rely heavily on threads. Also, on Linux what are the tools to debug my application while running on wine? I mean how i could find errors coming from wine... Thank you for you reply! I will test wine with my application as much as i can! Best Regards, Laurent