BitLevelCOM - C source code library that allows a calling user application to access serial communication ports (COM devices) under 32-bit MS Windows operating systems. It allows to transmit and receive data and control line signals (e.g. RTS, DTR)..
The free Neodeck Software Tool Tip control looks like the XP tool tip and allows you to display interactive help to your users. You can program the control to do whatever you want, from databound lists inside of it to appering anywhere on your form.