under their current licenses. Binary programs are licensed under a binary Software License Agreement. A fully open source simulator for the SPARC architecture also exists: RAMP Gold, a 32-bit, 64-thread SPARC Version 8 implementation, designed for FPGA-based architecture simulation. RAMP Gold is written in ~36,000 lines of SystemVerilog, and licensed under the BSD licenses. Supercomputers For HPC loads Fujitsu builds specialized SPARC64 fx processors with a new instruction extensions set, called HPC-ACE (High Performance Computing – Arithmetic Computational Extensions). Fujitsu's K computer ranked in the TOP500 June 2011 and November 2011 lists. It combines 88,128 SPARC64 VIIIfx CPUs, each with eight cores, for a total of 705,024 cores—almost twice as many as any other system in the TOP500 at that time. The K Computer was more powerful than the next five systems on the list combined, and had the highest performance-to-power ratio of any supercomputer system. It also ranked in the Green500 June 2011 list, with a score of 824.56 MFLOPS/W. In the November 2012 release of TOP500, the K computer ranked , using by far the most power of the top three. It ranked on the corresponding Green500 release. Newer HPC processors, IXfx and XIfx, were included in recent PRIMEHPC FX10 and FX100 supercomputers. Tianhe-2 (TOP500 as of November 2014) has a number of nodes with Galaxy FT-1500 OpenSPARC-based processors developed in China. However, those processors did not contribute to the LINPACK score. See also ERC32 — based on SPARC V7 specification Ross Technology, Inc. — a SPARC microprocessor developer during the 1980s and 1990s Sparcle — a modified SPARC with multiprocessing support used by the MIT Alewife project LEON — a space rated SPARC V8 processor. R1000 — a Russian quad-core microprocessor based on SPARC V9 specification Galaxy FT-1500 — a Chinese 16-core OpenSPARC based processor References External links SPARC International, Inc. SPARC Technical Documents OpenSPARC Architecture specification Hypervisor/Sun4v Reference Materials Fujitsu SPARC64 V, VI, VII, VIIIfx, IXfx Extensions and X / X+ Specification Fujitsu SPARC Roadmap SPARC processor images and descriptions The Rough Guide to MBus Modules (SuperSPARC, hyperSPARC) A quite an extensive list of operating systems supporting SPARC64 processors Computer-related introductions in 1985 Sun microprocessors 32-bit computers 64-bit computers