Xilinx Runtime (XRT) is implemented as as a combination of userspace and kernel driver components. XRT supports both PCIe based boards like U30, U50, U200, U250, U280, VCK190 and MPSoC based embedded platforms. XRT provides a standardized software interface to Xilinx FPGA. The key user APIs are defined in xrt.h header file.
Comprehensive documentation on xilinx.github.io/XRT