History

1992-1996

UltraCompressor II created by Nico de Vries. Releases v1.0 through v2.3 for DOS. Notable features: LZ77+Huffman compression, master-block deduplication, file versioning, and multi-volume spanning.

2015

Nico de Vries releases the source under LGPL-3.0 after a request from Vladislav Sagunov.

2020-2021

Jan Bobrowski writes unuc2/libunuc2, a clean-room portable decompressor in C.

2026

UC2 v3.0.0: cross-platform revival by Eremey Valetov. CMake build system, Linux/macOS/Windows/DOS targets, original compression engine reimplemented, Sphinx documentation, CI/CD pipeline.

Credits

  • Nico de Vries: original UC2 author

  • Danny Bezemer: co-developed the original UC2

  • Jan Bobrowski: portable decompressor (libunuc2)

  • Jan-Pieter Cornet: testing and format documentation

  • Vladislav Sagunov: requested the free-software source release

  • Eremey Valetov: v3.0.0 revival and ongoing development