GLIP, the "Generic Logic Interfacing Project", is a solution for transferring data through FIFOs between a host, usually a PC, and a target, usually a hardware component such as an FPGA or a microcontroller. The actual data transport can happen through various interfaces, such as USB 2.0, JTAG or TCP. GLIP encapsulates all low-level details of the data transfers and provides on the host side an easy to use C library, and on the target side ready to use interfaces (e.g. in Verilog) to quickly setup a working communication.
For more information, see http://glip.io.