I am not a Linux developer of any kind at the moment. That being said, I am trying to build a small application on an embedded touch screen PC. Assuming I can get the touch screen drivers to work, I am looking at using Puppy Linux because it runs on small systems and has a GUI. I don't know what programming language to use. I need to send messages over the ethernet port, read from the serial port, write to the parallel port, and have a GUI. I am not asking for any specifics, just a point in the write direction for language/technology selection. Much thanks.
C++ would be my choice for this as you have access to all the libraries you need to do all the things you want to do and still have flexibility to easily build a GUI using Gtk or Qt libraries.