edit, thanks marvel_boy for asking for some more info:
Short Description: Phabricator is an open-source software development platform. In Wikimedia, Phabricator is used for project management, software bug reporting and feature requests (see How to report a bug), and in the future also for code review in an integrated fashion. Link: https://www.mediawiki.org/wiki/Phabricator
Here is a link to Wikimedia's Phabricator in action: https://phabricator.wikimedia.org/