The TNI website is not currently working, so those looking for a copy of their very popular assembler can download version 0.45 here.

Main features:
- Multiple CPU support, even within the same source file
- Customised assembly, use the (pseudo-)instructions YOU like
- Ability to be compatible with other assemblers
- Multi-pass design
- Conditional assembly
- Local label mechanism
- Extensive expression parser with precedence levels
- Source and binary file inclusion
- Nestable block comments
- Output to multiple files
- Update/patch existing files