Hello,
we use in our development environment a SonarQube (http://docs.sonarqube.org/display/HOME/SonarQube+Platform) server for analyzing the technical quiality of our source code. One of the mandatory points on our checklist for code reviews is to check whether there are any major/critical/blocker SonarQube issues for the sources under review. This means, the reviewer has to open a new browser window, bring up the internal SonarQube web ui and looking for the source files under review.
My Idea now ist, that Collaborator makes use of the rich REST API of the SonarQube platform (http://docs.sonarqube.org/display/DEV/Web+API) and retrieves automatically any issues on the sources, which are reviewed and which are monitored in SonarQube. This probably means some configuration form mapping the sources to the SonarQube projects and components, but I think this should be feasible.
Best Regards,
Thomas