Can Coding Agents Relicense Open Source Through a ‘Clean Room’ Implementation of Code?

Simon Willison:

There are a lot of open questions about this, both ethically and legally. These appear to be coming to a head in the venerable chardet Python library. chardet was created by Mark Pilgrim back in 2006 and released under the LGPL. Mark retired from public internet life in 2011 and chardet’s maintenance was taken over by others, most notably Dan Blanchard who has been responsible for every release since 1.1 in July 2012.

Two days ago Dan released chardet 7.0.0 with the following note in the release notes:

Ground-up, MIT-licensed rewrite of chardet. Same package name, same public API — drop-in replacement for chardet 5.x/6.x. Just way faster and more accurate!

Yesterday Mark Pilgrim opened #327: No right to relicense this project.

A fascinating dispute, and the first public post from Pilgrim that I’ve seen in quite a while.

★ Sunday, 8 March 2026