Bazaar is an older distributed revision control system sponsored by Canonical which is still in use by many open source projects today. Most code review solutions don't work with Bazaar, but Review Board does!
RBTools makes it simple to post code reviews against Bazaar right from your command prompt, like so:
$ rbt post
Made some changes to your code, and want to update your review request? Just use
-r with your review request ID:
$ rbt post -r 123
What else does Review Board do?
Review Board gives you the tools you need to keep your code quality high, helping you build better products for happier customers. It integrates with many services and tools, including chat services, code hosting solutions, bug trackers, code analytics, and more.
Power Pack enhances Review Board further, providing document review, report generation, improved scalability, and more for your whole organization.