z80asm is an assembler for the Z80 microprcessor.  The assembler aims to be
portable and complete.

Features:
* All official mnemonics are recognized.
* Most unofficial mnemonics are recognized.
* Very complex expressions are allowed (bash style).
* Other source files can be included.
* Code can contain conditional parts.
* Beside the binary output file, a label file can be output with a list
  of all labels in the program. This label file is includable by other
  source files, so linker-like functionality can be obtained with it.
* There is support for listing files, with the input code and the assembled
  result next to each other.