No License Specified
The repository does not have a license, which generally means (according to the lawyers), that it can't be used.
I realise that Trivia is the de-facto standard for pattern matching, however it, and all the other pattern matchers I found for common lisp, have a GNU license, which isn't really accepted in commercial settings.
Assuming fare-matcher is released under a permissive license (BSD, MIT, Apache, etc), I'd like to use it instead of Trivia for certain projects.