[[wikipedia:JIRA|JIRA]] is non-open source bug tracking system. I am not sure why would open source project prefer closed source alternative to open source solutions like [[bugzilla]], but apparently many projects do and use [[JIRA]] as their issue tracker.

Few years ago, when [[NetBeans]] were migrating away from [[wikipedia:collabnet|CollabNet]] infrastructure, we almost ended up with [[JIRA]], but luckily the decision makers came (were forced to come) to their senses and we are using [[bugzilla]] now.