64tass is a cross-assembler which is nearly 100% compatible with
the original `Turbo Assembler', targeting the 65xx series of micro
processors.  It supports most of the features of the original
`Turbo Assembler Macro'.

Features:
- Open source portable C with minimal dependencies.
- Familiar syntax to Omicron TASS and TASM.
- Supports 6502, 65C02, R65C02, W65C02, 65CE02, 65816, DTV, 65EL02,
  4510.
- Arbitrary-precision integers and bit strings, double precision
  floating point numbers.
- Character and byte strings, array arithmetic.
- Handles UTF-8, UTF-16 and 8 bit RAW encoded source files, Unicode
  character strings.
- Supports Unicode identifiers with compatibility normalization and
  optional case insensitivity.
- Built-in "linker" with section support.
- Various memory models, binary targets and text output formats
  (also Hex/S-record).
- Assembly and label listings available for debugging or exporting.
- Conditional compilation, macros, structures, unions, scopes.