Can Coding Agents Relicense Open Source Through "Clean Room" Implementation?
Simon Willison's Blog·high signal
The chardet Python library maintainer used Claude Code to rewrite the codebase and relicensed from LGPL to MIT, claiming a "clean room" implementation. Original author Mark Pilgrim disputes this — the maintainer had decade-long exposure to the LGPL code, Claude referenced parts of the codebase during the rewrite, and Claude was likely trained on chardet. This is one of the first real-world legal tests of whether AI-assisted rewrites can justify relicensing. The Register covered it as "AI will ki