Flat Assembler is a fast and efficient self-assembling 80x86 assembler. It supports x86 and x86-64 instruction sets with MMX, 3DNow!, SSE up to SSE4, AVX, AVX2, and XOP extensions. It can produce output in binary, MZ, PE, COFF, or ELF format. It includes powerful but easy-to-use macroinstruction support and does multiple passes to optimize the instruction codes for size. It is written entirely in assembly language.
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.
The Amsterdam Compiler Kit is a fully-featured retargetable compiler toolchain. It will cross-compile ANSI C, K&R C, Pascal, Modula-2, Occam, Fortran and Basic for a number of architectures including, but not limited to, the 6500, 68000, Z80, i80, i86, i386, and PDP-11. It provides a complete development environment including preprocessors, compilers, assemblers, linkers, librarian tools, and target download tools.
nwbintools is a machine code tool-chain containing an assembler and various related development tools. It will thus be similar to GNU's binutils, but no attempts are made to duplicate its functionality, organization, or interfaces. The assembler works on x86 ELF-based Linux and FreeBSD systems.
cencode encodes a stream or a file into quoted c-string escape sequences, suitable for use directly in C code. It is a universal alternative to dedicated export formats like XPM, unportable resource forks, linker flags, and Windows resources where dynamic loading of external data is not possible or undesired.
The Java Binary Enhancement Tool (JBET) is a general Java program analysis and manipulation tool. Existing class files can be disassembled, eassembled, or edited programmatically through the JBET API. JBET can also be used to create new Java class files from scratch. It uses a convenient internal representation of all the contents of Java binary (.class) files, allowing the user to edit the classes easily, in a structured manner.