Crucible vs Review Board: What are the differences?
Crucible: Review code, discuss changes, share knowledge, and identify defects. Review code, discuss changes, share knowledge, and identify defects with Crucible's flexible review workflow. It's code review made easy for Subversion, CVS, Perforce, and more; Review Board: 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.
Crucible and Review Board can be categorized as "Code Review" tools.
Review Board is an open source tool with 1.2K GitHub stars and 359 GitHub forks. Here's a link to Review Board's open source repository on GitHub.