Thanks for the feedback-we're actually planning to open-source a version of our work that significantly improves on the original UDT project: https://udt.sourceforge.io/.
Look forward to it. I'd be interested to hear how your tool compares with Facebook WDT[1], as that would be my go-to right now if someone asked me for a fast point-to-point data transfer solution.
I don't have the expertise to determine whether it is "abandonware" or simply "done" I'm afraid. Found it a bit of a pain to use, hence why an alternative sounds interesting.