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Freeware
programming utilities: Assembler
Programming freeware: Assembler tools and sources
- The flat assembler is a fast and efficient
self-assembling 80x86 assembler for DOS, Windows, and Linux operating
systems. It supports all 8086-80486/Pentium instructions with MMX, SSE,
SSE2, SSE3, and 3DNow! extensions and x86-64 (both AMD64 and EM64T)
instructions. It can produce output in binary, MZ, PE, COFF, or ELF
format. It includes the powerful but easy-to-use macroinstruction
support, and does multiple passes to optimize the instruction codes for
size. The flat assembler is entirely written in assembly language.
http://freshmeat.net/projects/fasm/
http://www.flatassembler.net/ - MikeOS is an operating system for x86 PCs,
written entirely in assembler. It's not intended to to become a
fully-fledged general purpose OS. Instead, it's designed for learning
basic OS design and x86 assembly language. Consequently, it runs in
16-bit mode (for BIOS access) and has very low system requirements. It
features rudimentary DOS compatibility.
http://freshmeat.net/projects/mikeos/ - Yasm is a complete rewrite
of the NASM assembler. It currently supports the x86 and AMD64
instruction sets, accepts NASM and GAS assembler syntaxes, outputs
binary, ELF32, ELF64, COFF, Mach-O (32 and 64), RDOFF2, Win32, and
Win64 object formats, and generates source debugging information in
STABS, DWARF 2, and CodeView 8 formats.

http://freshmeat.net/projects/yasm - Easy Code for GoAsm: Visual assembly programming environment made to build 32-bit Windows applications.
http://www.freewarefiles.com/Easy-Code-GoAsm-V_program_27016.html
http://www.easycoder.org/
- Easy Code for Masm
Visual assembly programming environment made to build 32-bit Windows applications.
http://www.freewarefiles.com/Easy-Code-Masm-V_program_23623.html
http://www.easycoder.org/