What can I use for developing on FPGA (Virtex): C, C++, OpenCL, MPI?

What can I use for developing on FPGA (Virtex): C, C++, OpenCL, MPI?

What can I use for developing on FPGA Virtex-5 or Virtex-7: C, C++, C++11,
OpenCL, MPI? And what is mostly usually uses for this?