ATasm is a 6502 command-line cross-assembler that is compatible with the original Mac/65 macro assembler released by OSS software. The aim of ATasm is to provide Atari home-brew coders with a comfortable and powerful toolset.
Dev65 is a macro assembler, linker and librarian suite for the 6501, 6502, 65C02, 65816 and 65832 family of microprocessors coded in Java for portability. The code is based on a framework that could support other system architectures.