Copyright
nrvpack 3.03 — Atari ST NRV executable packer
Copyright © 2025–2026 exxos
This is an original, clean-room implementation of the NRV2B/NRV2E byte format. No source code from UCL, UPX, or any other GPL-licensed implementation was consulted or used.
Licensed under the MIT License with the following clarifications:
Compressed output files
Executables compressed with nrvpack (packed PRG / APP / TOS / TTP / ACC files) may be distributed, sold, or used for any purpose — commercial or otherwise — with no license obligation or attribution requirement. The small decompressor stub embedded in each packed file does not contaminate the containing program with any license terms. Just pack your program and ship it however you like.
Decompressor stub source
The 68k assembly decompressor stubs (stub.s,
stub_nrv2e.s, stub_xnrv2e.s,
stub_xnrv2e_p.s, stub_xnrv2e2.s,
stub_xnrv2et.s) are released
under the same MIT terms and are available for integration into demos,
games, intros, or other projects. Please credit
“exxos / nrvpack 3.03” in your project if you
use them.
Attribution for derivative works
If you base a new packer, encoder, or decompressor on nrvpack source or design, please credit the nrvpack 3.03 / exxos project as your starting point.
MIT License (standard text)
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
The Software is provided “as is”, without warranty of any kind, express or implied, including but not limited to the warranties of merchantability, fitness for a particular purpose and non-infringement. In no event shall the authors or copyright holders be liable for any claim, damages or other liability, whether in an action of contract, tort or otherwise, arising from, out of or in connection with the Software or the use or other dealings in the Software.