Fisheye vs Review Board: What are the differences?
Developers describe Fisheye as "Search, track, and visualize code changes". FishEye provides a read-only window into your Subversion, Perforce, CVS, Git, and Mercurial repositories, all in one place. Keep a pulse on everything about your code: Visualize and report on activity, integrate source with JIRA issues, and search for commits, files, revisions, or people. On the other hand, Review Board is detailed as "Stress-free code review for teams of all sizes". Review Board is an open source, web-based code and document review tool built to help companies, open source projects, and other organizations keep their quality high and their bug count low.
Fisheye and Review Board are primarily classified as "Code Search" and "Code Review" tools respectively.
Review Board is an open source tool with 1.19K GitHub stars and 359 GitHub forks. Here's a link to Review Board's open source repository on GitHub.