FPGA-CF is an open-source, portable, extensible communications package that consists of a small hardware core (less than 600 slices) and and a host-software library/API (Java and C++). It enables a host PC to transmit data at 120 Mb/s to XIlinx-based FPGA boards via Ethernet using standard internet protocols (UDP/IP). A custom lightweight connection-oriented protocol guarantees reliability. The hardware core is directly connected to the Xilinx internal configuration port (ICAP) and supports all ICAP functionality. The core also provides an extensible user-channel interface and provides up to 15, 8-bit user-data channels that can be connected to user circuitry (configurable by the user). The host software API supports both Java and C++ and provides high-level functionality for making connections and transmitting data.