Download Generic Windows XP, Windows Vista, Windows 7, Windows 8, Server 2003 (2k3), Server 2008 (2k8) (R2) 32/64-bit drivers
Download Official Mac OS X Universal Binary Driver v1.4.0. OS X 10.6, 10.7, 10.8. Snow Leopard Mountain Lion.
Download Official Prolific 2303 Universal Binary Driver v1.2.1r2. OSX 10.1 and above (Power PC). OSX 10.4 and 10.5 (Universal).
DownloadOpen Source 32 and 64 bit driver for Prolific 2303 (KEXT) for Mac OS X 10.6 (Snow Leopard) 10.7 (Lion) and maybe 10.8 (Snow Mountain Tiger Cat Lion)
Download Open Source Prolific 2303 KEXT for Mac OS X Lion (alternate build)
Download Open Source Prolific 2303 KEXT for Mac OS X 10.4 (Tiger) 10.5 (Leopard) 10.6 (Snow Leopard) 32 bit