Linux Debug is a functional clone of the old DOS debug.com for x86 linux. Functions include the ability to alter/examine memory and registers, set/clear breakpoints, step into and trace over, symmetric symbolic disassembler, and symbolic assembler. It has a simplified UI, and can work with bin and elf format files. Symbolic functions work only if debug symbols available in the file header. It features a NASM-compatible syntax for both disassembler and single line assembler.
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.