4.a. Linux Driver
No driver installation is necessary to use the Pololu USB AVR Programmer in Linux. The Linux Kernel comes with a USB-to-serial driver (the cdc_acm module) that automatically works with the programmer. (The source code for this driver is in the kernel source under drivers/usb/class/cdc-acm.c.)
When you plug your programmer into a Linux computer, the CDC ACM driver should automatically detect it and create two serial port devices. Unless you have other devices plugged in that use the CDC ACM driver, the names of these two serial port devices should be /dev/ttyACM0 for the programming port and /dev/ttyACM1 for the USB-to-TTL-serial adapter.
If the programmer is plugged in, but you do not see these devices, please see Troubleshooting (Section 8) for help identifying and fixing the problem.