h2incn tries to directly convert C/C++ headers to Nasm-style include files, and can be used in a makefile. It is useful if you want to use the same structures or external variable declarations in C and assembler code, and you don't want to use two separate files and update both each time you change something. It is written in a mix of C and C++ code. It currently works for simple files.
Classfile Reader & Writer is a Java package that makes it easy to read and write Java class files. It does not provide any help with displaying the contents of a class file (besides debug output) or disassembe the byte codes, but can read "obfuscated" class files such as those generated by Crema.
shellforge enables you to write shellcode programs in C. It transforms C program code into shellcode that will run on a Linux/x86 system. It provides macros to substitute libc calls with direct system calls and a Python script to automate compilation, extraction, encoding, and tests.
Aasm is an advanced modular assembler designed to support several target architectures. It has been designed to be easily extended. Its global architecture takes advantages of dynamic libraries to provide input, assembler and output modules. The input module supports Intel syntax (like nasm, tasm, masm, etc.). The x86 assembler module supports all opcodes up to P6 including MMX, SSE and 3DNow! extensions. F-CPU and SPARC assembler modules are under development. Several output modules are available for ELF, COFF, IntelHex, and raw binary formats. Advanced features include symbol scopes, an expressions engine, big integer support, macro capability, and numerous and accurate warning messages (over 300).
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.
asfpga is an assembler written for use in FPGA design. It can be easily modified for a particular instruction set. The ultimate goal of this software is to allow a FPGA designer to easily write assembly code for a custom instruction set. The current version allows you to create a listing file, a memory dump file which can be used in debugging HDL code using $readmemh() or equivalent routine, and a binary file which can be used to program an EPROM.
masmz80 is a very lightweight assembler for the Zilog Z80 processor. Objects generated contain information about global symbols, unreferenced symbols, and sections that need to be relocated, so it's easy to write code in many files and reference one project files' symbols from another. Linking these objects using included mlinkz80 produces an image ready for burning on an (E)EPROM.