I don't know about selling, but I had a hobby project, my first in Pascal, that would translate ProBoard (ProBBS, or a PcBoard door program that did fancy thing

I don't know about selling, but I had a hobby project, my first in Pascal, that would translate ProBoard (ProBBS, or a PcBoard door program that did fancy things) to and from RBBS (the other open source board software). I uploaded it to a couple of boards, some of which were FidoNet connected. Anyway, a few months later got a call I think from someone somewhere in the Navy that wanted to use it, and asked if I had any improvements planned. I didn't as I had already moved on to other things (probably Lemmings), but let them know they were free to use it as they see fit. As an 8 or 9 year old kid, I was amazed at the reach of technology, so it was very encouraging, and helped me to pursue a career in IT.