Back in my academic days I needed a PIC programmer. PIC programmers were a little bit expensive in Venezuela (maybe they still are). So I looked online for one that I could build myself.
I thought I could build more of the JDM programmers and sell them to my fellow classmates. I built some and sold a few of them. Unfortunetely some of the programmers didn't work on some computers, the problem was that the JDM takes power from the serial port, some serial ports didn't seem to provide enough power, particulary laptops.
I modified the circuit so it would use an external power supply.
I designed a PCB for it and brand it under my company name: