Best Esprint: free X driver for HP Designjet 10PS / 20PS / 50PS – Macitynet.it
From the BestSprint website you can download a free driver that allows you to use the HP Designjet 10PS / 20PS / 50PS printers under Mac OS X. The driver can use ColorSync and Quartz for data preparation. The driver works on any machine in which Mac OS X10.1 or higher is installed and a printer of those indicated connected via the USB port. It contains 3 paper profiles and from the site it is possible to download additional ones. Mac OS X 10.1 or higher is required.
To download it, start from this page.