Puppet Labs is the Portland, OR based company behind the amazing open source configuration management framework, Puppet. They use Redmine for issue tracking, the best open source issue tracker in my humble opinion. Puppet Labs wanted their Redmine instance to reflect their branding and generally look great, so we migrated their existing Wordpress theme to Redmine.
It's not often that I take on a non-Drupal project these days, but I couldn't resist the chance to work with so many great platforms and organizations.