Jira is an issue tracking and project management tool developed by Atlassian in 2002 using Java. It allows companies like Pinterest, Twitter, and Udemy to track bugs and manage agile projects. Jira provides out-of-the-box workflows that can also be customized, and integrates with other Atlassian tools like Trello and Bitbucket to allow teams to plan, track, release, and report on software development from a single system.