libFTDI is an open source library to talk to FTDI chips: FT232BM,
FT245BM, FT2232C, FT2232D and FT245R, including the popular bitbang
mode. The library is linked with your program in userspace, no
kernel driver required.
libFTDI works perfectly with Linux, Windows, MacOS X and BSD variants
thanks to libusb.