USBasp - USB programmer for Atmel AVR controllers - fischl.de
https://fischl.de/usbasp/
USBasp is a USB in-circuit programmer for Atmel AVR controllers. The following packages include circuit and firmware. usbasp.2011-05-28.tar.gz (519 kB) TPI support...
GitHub - aleh/usbisp: USBasp firmware working with a clone...
https://github.com/aleh/usbisp
This is a fork of the original USBasp firmware (the file from 2011-05-28) tweaked to work with clone "USB ISP Version 2.0" devices (marked "MX-USBISP-V4.00" on the PCB).