Hi all, I am developing a driver for communication with some PLC's. First, I thought to create a win32 dll, but because I need to be able to send and receive messages, I start using MFC. One of the requirements of the driver was that it could be used in VC++, Visual Basic, VB.NET, C# (so a lot of different languages). Well, because I have developed a class that needs to be called in the dll (so you can use driver->Connect() and so on), I needed to export a class. But, in this case, other languages such as visual basic wouldn't understand the dll. Then, someone gave me the advice to use COM objects. Well, it seems very hard to learn using COM, and some people say it will not be used anymore soon. Now is my question, what is the best way to develop this driver??? Thanks! Geert [url]http://geert.yoki.org[/url]