tl;dr: Review the plan at the end directly.

Vote Up/Down is a drupal module that uses Voting API to provide a way to vote.

In the last months I have been incrementally rewriting the scripts behind the stats I weekly publish about

I have been writing about Drupal core statistics several times in the past, and incrementally, I have been automating the process of extract/sanitize contributors from commit messages and generating visualizations of the contributions.