Co-Array Fortran

HPJava is an instance of what we call the HPspmd model: arguably it is not exactly a high-level parallel programming language in the ordinary sense, but rather a tool to assist parallel programmers in writing SPMD code. In this respect the closest recent language we are familiar with is probably Co-Array Fortran [22]. But HPJava and Co-Array Fortran have many obvious differences. In Co-Array Fortran array subscripting is local by default, or involves a combination of local subscripts and explicit process ids. There is no analogue of global subscripts, or HPF-like distribution formats. In Co-Array Fortran the logical model of communication is built into the language--remote memory access with intrinsics for synchronization. In HPJava, there are no communication primitives in the language itself. We follow the MPI philosophy of providing communication through separate libraries.