Funded by the Japanese government, the University of Tokyo, University of Tsukuba, and Kyoto University are developing a seamless and highly productive parallel programming environment for high performance computing. Started in 2008, this four-year research and development initiative aims to provide a new portable, efficient, and convenient parallel programming environment for a variety of machines, such as small-scale to large-scale PC clusters and next-generation petascale supercomputers. Researchers are developing a new parallel programming language, numerical libraries, and runtime systems. After presenting an overview of the project, researchers will discuss the portable, single runtime environment developed at the University of Tokyo, which consists of a portable user-level file system and an implementation-independent MPI runtime system. Using this runtime environment, the binary code developed in the PC cluster may run in a supercomputer center, although the supercomputer runtime environment is different. The presentation will conclude with a preview of future research efforts.