acme - 1:0.96.2-1 main

This is a cross assembler that can produce code for the following
processors: 6502, 6510 (including illegal opcodes), 65c02 and 65816.
ACME supports the standard assembler stuff like global/local/anonymous
labels, offset assembly, conditional assembly and looping assembly.
It can include other source files as well as binaries while assembling.
Calculations can be done in integer or float mode. Oh, and it is fast.