FASM
FASM (flat assembler) in computing is an assembler. It supports programming in Intel-style assembly language on the IA-32 and x86-64 computer architectures. It claims high speed, size optimizations, operating system (OS) portability, and macro abilities. It is a low-level assembler and intentionally uses very few command-line options (see SSSO principle). It is free and open source software.
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