Obd2 sample source code

Hey folks

I don’t know if this forum is the best place to post this questions but here goes. I’m a software developer looking to build a Obd2 scanner for windows and windows based PDA. I’m just starting my research and thought this forum would be a good start. What I’m looking for is some sample source code and or ActiveX objects I can use. Can anyone point me in the right direction?

Thanks