As (Unix)

as is a generic name for an assembler on Unix. On many systems the standard or pre-installed assembler is the GNU Assembler, commonly called GAS, whose executable is simply named as. This often causes the generic as to be often mistaken for the GNU Assembler. This problem is infrequent with many other assemblers if they have unique executable names; such as the Netwide Assembler, or NASM, whose executable name is its abbreviation, nasm.