JIRA is a development management tool used by VIVO and Vitro. See http://jira.duraspace.org for collections of issues pertaining to VIVO and other Duraspace projects.
There are many JIRA resources on-line – resources from Atlassian, the makers of JIRA, and otehrs from development teams around the world that use JIRA.
VIVO uses JIRA in a very simple way, organizing more than 1000 open and closed issues into "components" – issues that address a common concept such as ontology. We regularly review the open JIRA issues to see if work is underway, or if the issue continues to be relevant given other work on the project. We may ask people who open issues to clarify their issues. We may ask people if their issue can be closed.
The best way to learn about JIRA is to explore. If you have a Duraspace account, visit http://jira.duraspace.org If you do not have a Duraspace account, you can get one by sending email to sysadmin@duraspace.org