Delphi used to be able to generate one executable and not need any other run-time libraries etc. I'm not sure if this is the case with the latest tools - I use Delphi5 and Asyncpro and you could get a sizeable application in 1mb. It used to be that I liked to have utilities that fitted onto a floppy disk - with memory sticks, the 1.44mb boundary no longer exists!

With Delphi5 and Asynchpro, you can 'write' a terminal program with no code! Plonk a serial object onto the window, then plonk a terminal object on the window. configure coms ports,baud rates etc then press F9. Terminal program. If you want pull down menus to select com port,baud rate etc - that takes a little coding.

If you use USB chips that have drivers already written, that saves a lot of work writing your own. Or you can use existing drivers like the HID spec and make your microprocessor USB device behave that way. Obviously, if you have specific requirements for the USB interface, then you have to write your own drivers - c/c++ microsoft tools are required methinks.