It's easy to find the email addresses of Quod Libet's authors and maintainers, but please don't email us directly unless asked to, or if it concerns us specifically. If you contact just us, it means no one else can help you, and we can be really bad about replying to email.
The best way to report bugs is using the GitHub issue tracker.
For tips on how to report bugs see the Contributing Guide <BugReports>
If you're not sure if the behavior is a bug, or if you have other questions, the best way to contact us is through the quod-libet-devel Google group.
Quod Libet has an IRC channel on OFTC , #quodlibet. IRC is not a good place to report bugs; we'll just refer you to the mailing list if you try. It is a good place to ask for help with installation and configuration, or discuss development (assuming people there are paying attention).