According to github https://github.com/ppelleti/json65 C 47.1%, Assembly 40.4%, Perl 9.4%, Haskell 3.1%.

Yes, it actually contains perl and haskell code [0].

[0]: https://github.com/ppelleti/json65/blob/master/run-tests.pl https://github.com/ppelleti/json65/tree/master/tools