NASM is described as 'The Netwide Assembler, NASM, is an 80x86 and x86-64 assembler designed for portability and modularity. It supports a range of object file formats, including Linux and *BSD a.out, ELF, COFF, Mach-O, Microsoft 16-bit OBJ, Win32 and Win64. It will also output plain binary files' and is an app in the development category. There are seven alternatives to NASM for Windows, Linux, Haiku and Mac. The best NASM alternative is Yasm, which is both free and Open Source. Other great apps like NASM are flat assembler, Pelles C, Easy code and MASM Builder.
Yasm is a complete rewrite of the NASM assembler. It supports the x86 and AMD64 instruction sets, accepts NASM and GAS assembler syntaxes and outputs binary, ELF32 and ELF64 object formats.
The flat assembler is a fast and efficient self-assembling x86 assembler for DOS, Windows and Linux operating systems. Currently it supports x86 and x86-64 instructions sets with MMX, 3DNow!, SSE up to SSE4, AVX, AVX2 and XOP extensions, can produce output in plain binary, MZ...
Pelles C is a comprehensive development suite that can help you create apps compatible with Windows and ARM platforms.
Easy Code is the visual assembly programming environment made to build 32-bit Windows applications. The Easy Code interface, looking like Visual Basic, allows you to program Windows assembler applications (executable files, dynamic and static libreries, COFF object files...
MASM Builder is a free Integrated Development Environment IDE for developing 32-bit Windows programs using the Assembler. MASM Builder contains many useful features which will assist you in creating Windows API based programs.
Flasm is a free command line assembler/disassembler of Flash ActionScript bytecode. It lets you make changes to any SWF. Flasm fully supports SWFs produced by Macromedia Flash 8 and earlier.
JWasm is a Masm v6 compatible assembler. It's released under the Sybase Open Watcom Public License 1.0. JWasm can be used for virtually any purpose, unlike Microsoft's free download of current Masm versions, which are for non-commercial use only.
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