spim is a self-contained software simulator for running R2000/R3000 assembly language programs. It reads and can immediately execute files containing assembly language code. spim also provides a debugger and simple set of operating system services. spim provides both a simple, textual interface and a fancier, graphical interface. The package includes complete source code and documentation.
WLA DX is yet another macro assembler that can program the GB-Z80, Z80, 6502, 65c02, 6510, 65816, HuC6280, and SPC-700 CPUs. Included in the package there is a GB-Z80 disassembler and few converters. WLA DX was initially programmed to compile ROM images for Gameboy, but nowadays it can also patch existing ROM images with code, and even compile program files and ROM files for other CPUs like the NES-6502, C64-6510, and SNES's SPC-700.
An almost ISO C compatible C compiler that produces binaries for 6502-based computers. Targets that are supported out of the box are: Apple ][, Atari 8-bit machines, Commodore C64/C128/C16/C116, Commodore Plus/4, Commodore 600/700, GEOS for C64, and Lynx. The package includes a complete suite of assembler development tools (assembler, linker, archiver) which allows mixing of C and assembler code.
joeq is a Java 2 (JDK 1.3 and 1.4) compatible virtual machine. It is unique in that it is entirely implemented in Java, leading to greater reliability, portability, maintainability, and efficiency. It is also language-independent, so code from any supported language can be seamlessly compiled, linked, and executed dynamically.
Chump is a table-driven assembler and dissembler with a very fast new architecture input format. Both the assembler and disassembler are created using a single description. It comes with descriptions for ARM, MIPS, Stump, and 6809. It is intended for use as a library compiled with other programs to allow line assembly and disassembly.
PopAsm is an assembler (an assembly language compiler) designed to support the syntaxes of TASM/MASM and NASM, gathering together the best features of each of them. It is intended that it will support all instructions from Intel compatible CPUs, including MMX, 3DNow!, and SSE extensions.
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.