The talk provides a technical view of how to use, extend and contribute to the Metrics-Grimoire project, which produces a set of tools that can be used to analyze many kinds of software development repositories, from git or Subversion to Bugzilla, Jira or the SourceForge, GitHub and Launchpad issue trackers. Some related tools (from the vizGrimoire toolset) allow for different kinds of analysis and visualization of the retrieved data. When combined, quantitative data and charts about many different aspects of any free software project can be obtained, gaining knowledge about its evolution, performance, community, source code structure, etc. Being all the tools free software, the limit for the kind of analysis and visualizations is only the imagination. FLOSS (free, libre, open source software) projects are usually developed in the open. A lot of information about their inner life is available in their development repositories: source code management (aka version control), issue tracking (aka bug reporting) systems, mailing lists, etc. This information can be organized and analyzed, and be used to gain understanding about how the project is performing, about the processes their developers are using, and in general about how it is evolving. The kind of quantitative analytics that can be obtained from these repositories allow also for a direct tracking of several parameters that can characterize specific aspects of software development. The impact of changes in project policies or uses can therefore be evaluated quantitatively, and be observed in retrospective.