Do you use software peer reviews? Are you happy with your current code review practices? Even though formal inspection is recognized as one of the most effective ways to improve software quality, many software organizations struggle to effectively implement a formal inspection regime. Open source projects use an agile peer review process-based on asynchronous, frequent, incremental reviews that are carried out by invested codevelopers-that contrasts with heavyweight inspection processes. The authors describe lessons from the OSS process that transfer to proprietary software development. They also present a selection of popular tools that support lightweight, collaborative, code review processes and nonintrusive metric collection.